From 6f06ea48185a4dddfc01042ca1c12bb7dc89659c Mon Sep 17 00:00:00 2001
From: GitHub Actions <actions@github.com>
Date: Tue, 5 Mar 2024 00:22:45 +0000
Subject: [PATCH] site deploy

Auto-generated via {sandpaper}
Source  : 78694fed6337d3112700e6684294fd4b8ec5ceb1
Branch  : md-outputs
Author  : GitHub Actions <actions@github.com>
Time    : 2024-01-17 01:58:02 +0000
Message : markdown source builds

Auto-generated via {sandpaper}
Source  : f40c0b5e9582c3ec73cf5305784d272ec631367c
Branch  : main
Author  : Benson Muite <bkmgit@users.noreply.github.com>
Time    : 2024-01-17 01:57:00 +0000
Message : Merge pull request #1449 from emiliobiz/patch-1

Fix spelling mistake in 04-pipefilter.md
---
 01-intro.html                    |   17 +-
 02-filedir.html                  |  151 ++---
 03-create.html                   |  323 +++++----
 04-pipefilter.html               |   79 ++-
 05-loop.html                     |  292 ++++----
 06-script.html                   |  160 +++--
 07-find.html                     |   87 ++-
 404.html                         |    4 +-
 CODE_OF_CONDUCT.html             |    2 +-
 LICENSE.html                     |    2 +-
 aio.html                         | 1066 ++++++++++++++---------------
 discuss.html                     |    2 +-
 images.html                      |    4 +-
 index.html                       |   13 +-
 instructor-notes.html            |   14 +-
 instructor/01-intro.html         |   17 +-
 instructor/02-filedir.html       |  153 ++---
 instructor/03-create.html        |  323 +++++----
 instructor/04-pipefilter.html    |   79 ++-
 instructor/05-loop.html          |  292 ++++----
 instructor/06-script.html        |  160 +++--
 instructor/07-find.html          |   87 ++-
 instructor/404.html              |    4 +-
 instructor/CODE_OF_CONDUCT.html  |    2 +-
 instructor/LICENSE.html          |    2 +-
 instructor/aio.html              | 1068 +++++++++++++++---------------
 instructor/discuss.html          |    2 +-
 instructor/images.html           |    4 +-
 instructor/index.html            |   13 +-
 instructor/instructor-notes.html |   14 +-
 instructor/key-points.html       |    4 +-
 instructor/profiles.html         |    4 +-
 instructor/reference.html        |    2 +-
 key-points.html                  |    4 +-
 pkgdown.yml                      |    4 +-
 profiles.html                    |    4 +-
 reference.html                   |    2 +-
 37 files changed, 2198 insertions(+), 2262 deletions(-)

diff --git a/01-intro.html b/01-intro.html
index f36578bcf..b4e252d9d 100644
--- a/01-intro.html
+++ b/01-intro.html
@@ -362,7 +362,7 @@ <h3 id="the-shell">The Shell<a class="anchor" aria-label="anchor" href="#the-she
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span></span></code></pre>
 </div>
 <p>The shell typically uses <code>$</code> as the prompt, but may use a
 different symbol. In the examples for this lesson, we’ll show the prompt
@@ -382,7 +382,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb2">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="ex">nelle@localhost</span> $</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" tabindex="-1"></a><span class="ex">nelle@localhost</span> $</span></code></pre>
 </div>
 <p>The prompt might even include more than this. Do not worry if your
 prompt is not just a short <code>$</code>. This lesson does not depend
@@ -395,7 +395,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -403,20 +403,19 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <pre class="output" tabindex="0"><code>Desktop     Downloads   Movies      Pictures
 Documents   Library     Music       Public</code></pre>
 </div>
-<div id="command-not-found" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="command-not-found" class="callout-inner">
-<h3 class="callout-title">Command not found<a class="anchor" aria-label="anchor" href="#command-not-found"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="command-not-found">Command not found<a class="anchor" aria-label="anchor" href="#command-not-found"></a></h3>
 <div class="callout-content">
 <p>If the shell can’t find a program whose name is the command you
 typed, it will print an error message such as:</p>
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ks</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> ks</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -542,7 +541,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/01-intro.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-06-09",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/02-filedir.html b/02-filedir.html
index 722f1412b..2b73b91d5 100644
--- a/02-filedir.html
+++ b/02-filedir.html
@@ -331,7 +331,7 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -340,13 +340,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 <p>Here, the computer’s response is <code>/Users/nelle</code>, which is
 Nelle’s <strong>home directory</strong>:</p>
-<div id="home-directory-variation" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="home-directory-variation" class="callout-inner">
-<h3 class="callout-title">Home Directory Variation<a class="anchor" aria-label="anchor" href="#home-directory-variation"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="home-directory-variation">Home Directory Variation<a class="anchor" aria-label="anchor" href="#home-directory-variation"></a></h3>
 <div class="callout-content">
 <p>The home directory path will look different on different operating
 systems. On Linux, it may look like <code>/home/nelle</code>, and on
@@ -385,13 +384,12 @@ <h3 class="callout-title">Home Directory Variation<a class="anchor" aria-label="
 first part of its name. Similarly, we know that <code>/Users</code> is
 stored inside the root directory <code>/</code> because its name begins
 with <code>/</code>.</p>
-<div id="slashes" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="slashes" class="callout-inner">
-<h3 class="callout-title">Slashes<a class="anchor" aria-label="anchor" href="#slashes"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="slashes">Slashes<a class="anchor" aria-label="anchor" href="#slashes"></a></h3>
 <div class="callout-content">
 <p>Notice that there are two meanings for the <code>/</code> character.
 When it appears at the front of a file or directory name, it refers to
@@ -416,7 +414,7 @@ <h3 class="callout-title">Slashes<a class="anchor" aria-label="anchor" href="#sl
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -441,7 +439,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -453,13 +451,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <strong>sub-directories</strong>. Any names in the output that don’t
 have a classification symbol are <strong>files</strong> in the current
 working directory.</p>
-<div id="clearing-your-terminal" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="clearing-your-terminal" class="callout-inner">
-<h3 class="callout-title">Clearing your terminal<a class="anchor" aria-label="anchor" href="#clearing-your-terminal"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="clearing-your-terminal">Clearing your terminal<a class="anchor" aria-label="anchor" href="#clearing-your-terminal"></a></h3>
 <div class="callout-content">
 <p>If your screen gets too cluttered, you can clear your terminal using
 the <code>clear</code> command. You can still access previous commands
@@ -479,23 +476,22 @@ <h3 id="getting-help">Getting help<a class="anchor" aria-label="anchor" href="#g
 </ol><div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
 </div>
 <ol start="2" style="list-style-type: decimal"><li>We can read its manual with <code>man</code> (available on Linux and
 macOS):</li>
 </ol><div class="codewrapper sourceCode" id="cb8">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
 </div>
 <p>We’ll describe both ways next.</p>
-<div id="help-for-built-in-commands" class="callout callout">
+<div id="callout4" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="help-for-built-in-commands" class="callout-inner">
-<h3 class="callout-title">Help for built-in commands<a class="anchor" aria-label="anchor" href="#help-for-built-in-commands"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="help-for-built-in-commands">Help for built-in commands<a class="anchor" aria-label="anchor" href="#help-for-built-in-commands"></a></h3>
 <div class="callout-content">
 <p>Some commands are built in to the Bash shell, rather than existing as
 separate programs on the filesystem. One example is the <code>cd</code>
@@ -514,7 +510,7 @@ <h4 id="the---help-option">The <code>--help</code> option<a class="anchor" aria-
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -545,20 +541,19 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
   -F, --classify             append indicator (one of */=&gt;@|) to entries
 ...        ...        ...</code></pre>
 </div>
-<div id="unsupported-command-line-options" class="callout callout">
+<div id="callout5" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="unsupported-command-line-options" class="callout-inner">
-<h3 class="callout-title">Unsupported command-line options<a class="anchor" aria-label="anchor" href="#unsupported-command-line-options"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="unsupported-command-line-options">Unsupported command-line options<a class="anchor" aria-label="anchor" href="#unsupported-command-line-options"></a></h3>
 <div class="callout-content">
 <p>If you try to use an option that is not supported, <code>ls</code>
 and other commands will usually print an error message similar to:</p>
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-j</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-j</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -576,7 +571,7 @@ <h4 id="the-man-command">The <code>man</code> command<a class="anchor" aria-labe
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
 </div>
 <p>This command will turn your terminal into a page with a description
 of the <code>ls</code> command and its options.</p>
@@ -590,13 +585,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <kbd>Shift</kbd>+<kbd>N</kbd> (for moving backward).</p>
 <p>To <strong>quit</strong> the <code>man</code> pages, press
 <kbd>Q</kbd>.</p>
-<div id="manual-pages-on-the-web" class="callout callout">
+<div id="callout6" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="manual-pages-on-the-web" class="callout-inner">
-<h3 class="callout-title">Manual pages on the web<a class="anchor" aria-label="anchor" href="#manual-pages-on-the-web"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="manual-pages-on-the-web">Manual pages on the web<a class="anchor" aria-label="anchor" href="#manual-pages-on-the-web"></a></h3>
 <div class="callout-content">
 <p>Of course, there is a third way to access help for commands:
 searching the internet via your web browser. When using internet search,
@@ -631,7 +625,7 @@ <h3 class="callout-title">Exploring More<code>ls</code>Options<a class="anchor"
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>The <code>-l</code> option makes <code>ls</code> use a
 <strong>l</strong>ong listing format, showing not only the
@@ -667,7 +661,7 @@ <h3 class="callout-title">Listing in Reverse Chronological Order<a class="anchor
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>The most recently changed file is listed last when using
 <code>-rt</code>. This can be very useful for finding your most recent
@@ -691,7 +685,7 @@ <h3 id="exploring-other-directories">Exploring Other Directories<a class="anchor
 <div class="codewrapper sourceCode" id="cb14">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb14-1"><a href="#cb14-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb14-1"><a href="#cb14-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -722,7 +716,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb16">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop/shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop/shell-lesson-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -744,9 +738,9 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop</span>
-<span id="cb18-2"><a href="#cb18-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span>
-<span id="cb18-3"><a href="#cb18-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> cd Desktop</span>
+<span id="cb18-2"><a href="#cb18-2" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span>
+<span id="cb18-3"><a href="#cb18-3" tabindex="-1"></a><span class="ex">$</span> cd exercise-data</span></code></pre>
 </div>
 <p>These commands will move us from our home directory into our Desktop
 directory, then into the <code>shell-lesson-data</code> directory, then
@@ -763,7 +757,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -773,7 +767,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -786,7 +780,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb23">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -803,7 +797,7 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ..</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="ex">$</span> cd ..</span></code></pre>
 </div>
 <p><code>..</code> is a special directory name meaning “the directory
 containing this one”, or more succinctly, the <strong>parent</strong> of
@@ -813,7 +807,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -826,7 +820,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> <span class="at">-a</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> <span class="at">-a</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -844,13 +838,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <p>Note that in most command line tools, multiple options can be
 combined with a single <code>-</code> and no spaces between the options;
 <code>ls -F -a</code> is equivalent to <code>ls -Fa</code>.</p>
-<div id="other-hidden-files" class="callout callout">
+<div id="callout7" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="other-hidden-files" class="callout-inner">
-<h3 class="callout-title">Other Hidden Files<a class="anchor" aria-label="anchor" href="#other-hidden-files"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="other-hidden-files">Other Hidden Files<a class="anchor" aria-label="anchor" href="#other-hidden-files"></a></h3>
 <div class="callout-content">
 <p>In addition to the hidden directories <code>..</code> and
 <code>.</code>, you may also see a file called
@@ -872,14 +865,14 @@ <h3 class="callout-title">Other Hidden Files<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> cd</span></code></pre>
 </div>
 <p>How can you check what happened? <code>pwd</code> gives us the
 answer!</p>
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -896,7 +889,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data</span></code></pre>
 </div>
 <p>Check that we’ve moved to the right place by running <code>pwd</code>
 and <code>ls -F</code>.</p>
@@ -922,7 +915,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -932,17 +925,16 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd /Users/nelle/Desktop/shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> cd /Users/nelle/Desktop/shell-lesson-data</span></code></pre>
 </div>
 <p>Run <code>pwd</code> and <code>ls -F</code> to ensure that we’re in
 the directory we expect.</p>
-<div id="two-more-shortcuts" class="callout callout">
+<div id="callout8" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="two-more-shortcuts" class="callout-inner">
-<h3 class="callout-title">Two More Shortcuts<a class="anchor" aria-label="anchor" href="#two-more-shortcuts"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="two-more-shortcuts">Two More Shortcuts<a class="anchor" aria-label="anchor" href="#two-more-shortcuts"></a></h3>
 <div class="callout-content">
 <p>The shell interprets a tilde (<code>~</code>) character at the start
 of a path to mean “the current user’s home directory”. For example, if
@@ -965,20 +957,20 @@ <h3 class="callout-title">Two More Shortcuts<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span></code></pre>
 </div>
 <p>Then <code>cd</code> into the <code>exercise-data/creatures</code>
 directory</p>
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/creatures</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/creatures</span></code></pre>
 </div>
 <p>Now if you run</p>
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd <span class="at">-</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> cd <span class="at">-</span></span></code></pre>
 </div>
 <p>you’ll see you’re back in <code>~/Desktop/shell-lesson-data</code>.
 Run <code>cd -</code> again and you’re back in
@@ -1014,7 +1006,7 @@ <h3 class="callout-title">Absolute vs Relative Paths<a class="anchor" aria-label
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>No: <code>.</code> stands for the current directory.</li>
 <li>No: <code>/</code> stands for the root directory.</li>
@@ -1055,7 +1047,7 @@ <h3 class="callout-title">Relative Path Resolution<a class="anchor" aria-label="
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>No: there <em>is</em> a directory <code>backup</code> in
 <code>/Users</code>.</li>
@@ -1097,7 +1089,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5">Show me the solution</h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>No: <code>pwd</code> is not the name of a directory.</li>
 <li>Yes: <code>ls</code> without directory argument lists files and
@@ -1117,7 +1109,7 @@ <h4 class="accordion-header" id="headingSolution5">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
 </div>
 <figure><img src="fig/shell_command_syntax.svg" alt="General syntax of a shell command" class="figure mx-auto d-block"></figure><p><code>ls</code> is the <strong>command</strong>, with an
 <strong>option</strong> <code>-F</code> and an <strong>argument</strong>
@@ -1143,8 +1135,8 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span>
-<span id="cb42-2"><a href="#cb42-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-s</span> exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span>
+<span id="cb42-2"><a href="#cb42-2" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-s</span> exercise-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1159,7 +1151,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb44">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-S</span> exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-S</span> exercise-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1173,7 +1165,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1182,13 +1174,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 Library/              Users/
 Network/              Volumes/</code></pre>
 </div>
-<div id="when-to-use-short-or-long-options" class="callout callout">
+<div id="callout9" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="when-to-use-short-or-long-options" class="callout-inner">
-<h3 class="callout-title">When to use short or long options<a class="anchor" aria-label="anchor" href="#when-to-use-short-or-long-options"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="when-to-use-short-or-long-options">When to use short or long options<a class="anchor" aria-label="anchor" href="#when-to-use-short-or-long-options"></a></h3>
 <div class="callout-content">
 <p>When options exist as both short and long options:</p>
 <ul><li>Use the short option when typing commands directly into the shell to
@@ -1218,7 +1209,7 @@ <h3 id="nelles-pipeline-organizing-files">Nelle’s Pipeline: Organizing Files<a
 <div class="codewrapper sourceCode" id="cb48">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
 </div>
 <p>This command is a lot to type, but she can let the shell do most of
 the work through what is called <strong>tab completion</strong>. If she
@@ -1226,14 +1217,14 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb49">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls nor</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" tabindex="-1"></a><span class="ex">$</span> ls nor</span></code></pre>
 </div>
 <p>and then presses <kbd>Tab</kbd> (the tab key on her keyboard), the
 shell automatically completes the directory name for her:</p>
 <div class="codewrapper sourceCode" id="cb50">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
 </div>
 <p>Pressing <kbd>Tab</kbd> again does nothing, since there are multiple
 possibilities; pressing <kbd>Tab</kbd> twice brings up a list of all the
@@ -1244,15 +1235,15 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb51">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb51-1"><a href="#cb51-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/goo</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb51-1"><a href="#cb51-1" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/goo</span></code></pre>
 </div>
 <p>To see all of those files, she can press <kbd>Tab</kbd> twice
 more.</p>
 <div class="codewrapper sourceCode" id="cb52">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" aria-hidden="true" tabindex="-1"></a><span class="fu">ls</span> north-pacific-gyre/goo</span>
-<span id="cb52-2"><a href="#cb52-2" aria-hidden="true" tabindex="-1"></a><span class="ex">goodiff.sh</span>   goostats.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" tabindex="-1"></a><span class="fu">ls</span> north-pacific-gyre/goo</span>
+<span id="cb52-2"><a href="#cb52-2" tabindex="-1"></a><span class="ex">goodiff.sh</span>   goostats.sh</span></code></pre>
 </div>
 <p>This is called <strong>tab completion</strong>, and we will see it in
 many other tools as we go on.</p>
@@ -1355,7 +1346,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/02-filedir.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2024-01-08",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/03-create.html b/03-create.html
index 18488efcd..00f562d21 100644
--- a/03-create.html
+++ b/03-create.html
@@ -323,7 +323,7 @@ <h3 id="step-one-see-where-we-are-and-what-we-already-have">Step one: see where
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -335,8 +335,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/writing/</span>
-<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/writing/</span>
+<span id="cb3-2"><a href="#cb3-2" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -351,7 +351,7 @@ <h3 id="create-a-directory">Create a directory<a class="anchor" aria-label="anch
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> mkdir thesis</span></code></pre>
 </div>
 <p>As you might guess from its name, <code>mkdir</code> means ‘make
 directory’. Since <code>thesis</code> is a relative path (i.e., does not
@@ -360,7 +360,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb6">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -372,7 +372,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb8">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> thesis</span></code></pre>
 </div>
 <p>Note that <code>mkdir</code> is not limited to creating single
 directories one at a time. The <code>-p</code> option allows
@@ -381,7 +381,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> ../project/data ../project/results</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> ../project/data ../project/results</span></code></pre>
 </div>
 <p>The <code>-R</code> option to the <code>ls</code> command will list
 all nested subdirectories within a directory. Let’s use
@@ -390,7 +390,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-FR</span> ../project</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-FR</span> ../project</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -402,13 +402,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 
 ../project/results:</code></pre>
 </div>
-<div id="two-ways-of-doing-the-same-thing" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="two-ways-of-doing-the-same-thing" class="callout-inner">
-<h3 class="callout-title">Two ways of doing the same thing<a class="anchor" aria-label="anchor" href="#two-ways-of-doing-the-same-thing"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="two-ways-of-doing-the-same-thing">Two ways of doing the same thing<a class="anchor" aria-label="anchor" href="#two-ways-of-doing-the-same-thing"></a></h3>
 <div class="callout-content">
 <p>Using the shell to create a directory is no different than using a
 file explorer. If you open the current directory using your operating
@@ -419,13 +418,12 @@ <h3 class="callout-title">Two ways of doing the same thing<a class="anchor" aria
 </div>
 </div>
 </div>
-<div id="good-names-for-files-and-directories" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="good-names-for-files-and-directories" class="callout-inner">
-<h3 class="callout-title">Good names for files and directories<a class="anchor" aria-label="anchor" href="#good-names-for-files-and-directories"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="good-names-for-files-and-directories">Good names for files and directories<a class="anchor" aria-label="anchor" href="#good-names-for-files-and-directories"></a></h3>
 <div class="callout-content">
 <p>Complicated names of files and directories can make your life painful
 when working on the command line. Here we provide a few useful tips for
@@ -462,16 +460,15 @@ <h3 id="create-a-text-file">Create a text file<a class="anchor" aria-label="anch
 <div class="codewrapper sourceCode" id="cb12">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd thesis</span>
-<span id="cb12-2"><a href="#cb12-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano draft.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" tabindex="-1"></a><span class="ex">$</span> cd thesis</span>
+<span id="cb12-2"><a href="#cb12-2" tabindex="-1"></a><span class="ex">$</span> nano draft.txt</span></code></pre>
 </div>
-<div id="which-editor" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="which-editor" class="callout-inner">
-<h3 class="callout-title">Which Editor?<a class="anchor" aria-label="anchor" href="#which-editor"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="which-editor">Which Editor?<a class="anchor" aria-label="anchor" href="#which-editor"></a></h3>
 <div class="callout-content">
 <p>When we say, ‘<code>nano</code> is a text editor’ we really do mean
 ‘text’. It can only work with plain character data, not tables, images,
@@ -503,13 +500,12 @@ <h3 class="callout-title">Which Editor?<a class="anchor" aria-label="anchor" hre
 to accept the suggested default of <code>draft.txt</code>.</p>
 <p>Once our file is saved, we can use <kbd>Ctrl</kbd>+<kbd>X</kbd> to
 quit the editor and return to the shell.</p>
-<div id="control-ctrl-or-key" class="callout callout">
+<div id="callout4" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="control-ctrl-or-key" class="callout-inner">
-<h3 class="callout-title">Control, Ctrl, or ^ Key<a class="anchor" aria-label="anchor" href="#control-ctrl-or-key"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="control-ctrl-or-key">Control, Ctrl, or ^ Key<a class="anchor" aria-label="anchor" href="#control-ctrl-or-key"></a></h3>
 <div class="callout-content">
 <p>The Control key is also called the ‘Ctrl’ key. There are various ways
 in which using the Control key may be described. For example, you may
@@ -534,7 +530,7 @@ <h3 class="callout-title">Control, Ctrl, or ^ Key<a class="anchor" aria-label="a
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -554,7 +550,7 @@ <h3 class="callout-title">Creating Files a Different Way<a class="anchor" aria-l
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> touch my_file.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> touch my_file.txt</span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li><p>What did the <code>touch</code> command do? When you look at your
 current directory using the GUI file explorer, does the file show
@@ -605,18 +601,17 @@ <h3 class="callout-title">Creating Files a Different Way<em>(continued)</em><a c
 <div class="codewrapper sourceCode" id="cb16">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm my_file.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" tabindex="-1"></a><span class="ex">$</span> rm my_file.txt</span></code></pre>
 </div>
 </div>
 </div>
 </div>
-<div id="whats-in-a-name" class="callout callout">
+<div id="callout5" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="whats-in-a-name" class="callout-inner">
-<h3 class="callout-title">What’s In A Name?<a class="anchor" aria-label="anchor" href="#whats-in-a-name"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="whats-in-a-name">What’s In A Name?<a class="anchor" aria-label="anchor" href="#whats-in-a-name"></a></h3>
 <div class="callout-content">
 <p>You may have noticed that all of Nelle’s files are named ‘something
 dot something’, and in this part of the lesson, we always used the
@@ -651,7 +646,7 @@ <h3 class="callout-title">What’s In A Name?<a class="anchor" aria-label="ancho
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data/exercise-data/writing</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data/exercise-data/writing</span></code></pre>
 </div>
 <p>In our <code>thesis</code> directory we have a file
 <code>draft.txt</code> which isn’t a particularly informative name, so
@@ -660,7 +655,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv thesis/draft.txt thesis/quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> mv thesis/draft.txt thesis/quotes.txt</span></code></pre>
 </div>
 <p>The first argument tells <code>mv</code> what we’re ‘moving’, while
 the second is where it’s to go. In this case, we’re moving
@@ -671,7 +666,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -696,7 +691,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv thesis/quotes.txt .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">$</span> mv thesis/quotes.txt .</span></code></pre>
 </div>
 <p>The effect is to move the file from the directory it was in to the
 current working directory. <code>ls</code> now shows us that
@@ -704,7 +699,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -717,7 +712,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb24">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis/quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> ls thesis/quotes.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -732,7 +727,7 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -754,18 +749,18 @@ <h3 class="callout-title">Moving Files to a new folder<a class="anchor" aria-lab
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span>
-<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">analyzed/</span> raw/</span>
-<span id="cb28-3"><a href="#cb28-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> analyzed</span>
-<span id="cb28-4"><a href="#cb28-4" aria-hidden="true" tabindex="-1"></a><span class="ex">fructose.dat</span> glucose.dat maltose.dat sucrose.dat</span>
-<span id="cb28-5"><a href="#cb28-5" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd analyzed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span>
+<span id="cb28-2"><a href="#cb28-2" tabindex="-1"></a> <span class="ex">analyzed/</span> raw/</span>
+<span id="cb28-3"><a href="#cb28-3" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> analyzed</span>
+<span id="cb28-4"><a href="#cb28-4" tabindex="-1"></a><span class="ex">fructose.dat</span> glucose.dat maltose.dat sucrose.dat</span>
+<span id="cb28-5"><a href="#cb28-5" tabindex="-1"></a><span class="ex">$</span> cd analyzed</span></code></pre>
 </div>
 <p>Fill in the blanks to move these files to the <code>raw/</code>
 folder (i.e. the one she forgot to put them in)</p>
 <div class="codewrapper sourceCode" id="cb29">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ____/____</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ____/____</span></code></pre>
 </div>
 </div>
 </div>
@@ -780,7 +775,7 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ../raw</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ../raw</span></code></pre>
 </div>
 <p>Recall that <code>..</code> refers to the parent directory (i.e. one
 above the current directory) and that <code>.</code> refers to the
@@ -799,8 +794,8 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp quotes.txt thesis/quotations.txt</span>
-<span id="cb31-2"><a href="#cb31-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt thesis/quotations.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="ex">$</span> cp quotes.txt thesis/quotations.txt</span>
+<span id="cb31-2"><a href="#cb31-2" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt thesis/quotations.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -812,14 +807,14 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="at">-r</span> thesis thesis_backup</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="at">-r</span> thesis thesis_backup</span></code></pre>
 </div>
 <p>We can check the result by listing the contents of both the
 <code>thesis</code> and <code>thesis_backup</code> directory:</p>
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis thesis_backup</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> ls thesis thesis_backup</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -837,8 +832,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp thesis thesis_backup</span>
-<span id="cb36-2"><a href="#cb36-2" aria-hidden="true" tabindex="-1"></a><span class="ex">cp:</span> <span class="at">-r</span> not specified<span class="kw">;</span> <span class="ex">omitting</span> directory <span class="st">'thesis'</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> cp thesis thesis_backup</span>
+<span id="cb36-2"><a href="#cb36-2" tabindex="-1"></a><span class="ex">cp:</span> <span class="at">-r</span> not specified<span class="kw">;</span> <span class="ex">omitting</span> directory <span class="st">'thesis'</span></span></code></pre>
 </div>
 <div id="renaming-files" class="callout challenge">
 <div class="callout-square">
@@ -893,7 +888,7 @@ <h3 class="callout-title">Moving and Copying<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -903,7 +898,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -913,10 +908,10 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir recombined</span>
-<span id="cb41-2"><a href="#cb41-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv proteins.dat recombined/</span>
-<span id="cb41-3"><a href="#cb41-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp recombined/proteins.dat ../proteins-saved.dat</span>
-<span id="cb41-4"><a href="#cb41-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="ex">$</span> mkdir recombined</span>
+<span id="cb41-2"><a href="#cb41-2" tabindex="-1"></a><span class="ex">$</span> mv proteins.dat recombined/</span>
+<span id="cb41-3"><a href="#cb41-3" tabindex="-1"></a><span class="ex">$</span> cp recombined/proteins.dat ../proteins-saved.dat</span>
+<span id="cb41-4"><a href="#cb41-4" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li><code>proteins-saved.dat recombined</code></li>
 <li><code>recombined</code></li>
@@ -966,26 +961,25 @@ <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> rm quotes.txt</span></code></pre>
 </div>
 <p>We can confirm the file has gone using <code>ls</code>:</p>
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="error" tabindex="0"><code>ls: cannot access 'quotes.txt': No such file or directory</code></pre>
 </div>
-<div id="deleting-is-forever" class="callout callout">
+<div id="callout6" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="deleting-is-forever" class="callout-inner">
-<h3 class="callout-title">Deleting Is Forever<a class="anchor" aria-label="anchor" href="#deleting-is-forever"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="deleting-is-forever">Deleting Is Forever<a class="anchor" aria-label="anchor" href="#deleting-is-forever"></a></h3>
 <div class="callout-content">
 <p>The Unix shell doesn’t have a trash bin that we can recover deleted
 files from (though most graphical interfaces to Unix do). Instead, when
@@ -1038,7 +1032,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="ex">$</span> rm thesis</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1053,7 +1047,7 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb48">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm <span class="at">-r</span> thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" tabindex="-1"></a><span class="ex">$</span> rm <span class="at">-r</span> thesis</span></code></pre>
 </div>
 <p>Given that there is no way to retrieve files deleted using the shell,
 <code>rm -r</code> <em>should be used with great caution</em> (you might
@@ -1080,16 +1074,16 @@ <h3 class="callout-title">Copy with Multiple Filenames<a class="anchor" aria-lab
 <div class="codewrapper sourceCode" id="cb49">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir backup</span>
-<span id="cb49-2"><a href="#cb49-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp creatures/minotaur.dat creatures/unicorn.dat backup/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" tabindex="-1"></a><span class="ex">$</span> mkdir backup</span>
+<span id="cb49-2"><a href="#cb49-2" tabindex="-1"></a><span class="ex">$</span> cp creatures/minotaur.dat creatures/unicorn.dat backup/</span></code></pre>
 </div>
 <p>In the example below, what does <code>cp</code> do when given three
 or more file names?</p>
 <div class="codewrapper sourceCode" id="cb50">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd creatures</span>
-<span id="cb50-2"><a href="#cb50-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" tabindex="-1"></a><span class="ex">$</span> cd creatures</span>
+<span id="cb50-2"><a href="#cb50-2" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1099,7 +1093,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb52">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp minotaur.dat unicorn.dat basilisk.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" tabindex="-1"></a><span class="ex">$</span> cp minotaur.dat unicorn.dat basilisk.dat</span></code></pre>
 </div>
 </div>
 </div>
@@ -1128,13 +1122,12 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 </div>
 <div class="section level3">
 <h3 id="using-wildcards-for-accessing-multiple-files-at-once">Using wildcards for accessing multiple files at once<a class="anchor" aria-label="anchor" href="#using-wildcards-for-accessing-multiple-files-at-once"></a></h3>
-<div id="wildcards" class="callout callout">
+<div id="callout7" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="wildcards" class="callout-inner">
-<h3 class="callout-title">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="wildcards">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a></h3>
 <div class="callout-content">
 <p><code>*</code> is a <strong>wildcard</strong>, which represents zero
 or more other characters. Let’s consider the
@@ -1225,25 +1218,25 @@ <h3 class="callout-title">More on Wildcards<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb54">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb54-1"><a href="#cb54-1" aria-hidden="true" tabindex="-1"></a><span class="bu">.</span></span>
-<span id="cb54-2"><a href="#cb54-2" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
-<span id="cb54-3"><a href="#cb54-3" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
-<span id="cb54-4"><a href="#cb54-4" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
-<span id="cb54-5"><a href="#cb54-5" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
-<span id="cb54-6"><a href="#cb54-6" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
-<span id="cb54-7"><a href="#cb54-7" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
-<span id="cb54-8"><a href="#cb54-8" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
-<span id="cb54-9"><a href="#cb54-9" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
-<span id="cb54-10"><a href="#cb54-10" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
-<span id="cb54-11"><a href="#cb54-11" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
-<span id="cb54-12"><a href="#cb54-12" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
-<span id="cb54-13"><a href="#cb54-13" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
-<span id="cb54-14"><a href="#cb54-14" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> backup</span>
-<span id="cb54-15"><a href="#cb54-15" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
-<span id="cb54-16"><a href="#cb54-16" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
-<span id="cb54-17"><a href="#cb54-17" aria-hidden="true" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
-<span id="cb54-18"><a href="#cb54-18" aria-hidden="true" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
-<span id="cb54-19"><a href="#cb54-19" aria-hidden="true" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb54-1"><a href="#cb54-1" tabindex="-1"></a><span class="bu">.</span></span>
+<span id="cb54-2"><a href="#cb54-2" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
+<span id="cb54-3"><a href="#cb54-3" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
+<span id="cb54-4"><a href="#cb54-4" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
+<span id="cb54-5"><a href="#cb54-5" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
+<span id="cb54-6"><a href="#cb54-6" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
+<span id="cb54-7"><a href="#cb54-7" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
+<span id="cb54-8"><a href="#cb54-8" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
+<span id="cb54-9"><a href="#cb54-9" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
+<span id="cb54-10"><a href="#cb54-10" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
+<span id="cb54-11"><a href="#cb54-11" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
+<span id="cb54-12"><a href="#cb54-12" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
+<span id="cb54-13"><a href="#cb54-13" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
+<span id="cb54-14"><a href="#cb54-14" tabindex="-1"></a><span class="ex">├──</span> backup</span>
+<span id="cb54-15"><a href="#cb54-15" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
+<span id="cb54-16"><a href="#cb54-16" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
+<span id="cb54-17"><a href="#cb54-17" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
+<span id="cb54-18"><a href="#cb54-18" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
+<span id="cb54-19"><a href="#cb54-19" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span></code></pre>
 </div>
 <p>Before heading off to another field trip, she wants to back up her
 data and send some datasets to her colleague Bob. Sam uses the following
@@ -1251,57 +1244,57 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb55">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb55-1"><a href="#cb55-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>dataset<span class="pp">*</span> backup/datasets</span>
-<span id="cb55-2"><a href="#cb55-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp ____calibration____ backup/calibration</span>
-<span id="cb55-3"><a href="#cb55-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp 2015-____-____ send_to_bob/all_november_files/</span>
-<span id="cb55-4"><a href="#cb55-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp ____ send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb55-1"><a href="#cb55-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>dataset<span class="pp">*</span> backup/datasets</span>
+<span id="cb55-2"><a href="#cb55-2" tabindex="-1"></a><span class="ex">$</span> cp ____calibration____ backup/calibration</span>
+<span id="cb55-3"><a href="#cb55-3" tabindex="-1"></a><span class="ex">$</span> cp 2015-____-____ send_to_bob/all_november_files/</span>
+<span id="cb55-4"><a href="#cb55-4" tabindex="-1"></a><span class="ex">$</span> cp ____ send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
 </div>
 <p>Help Sam by filling in the blanks.</p>
 <p>The resulting directory structure should look like this</p>
 <div class="codewrapper sourceCode" id="cb56">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb56-1"><a href="#cb56-1" aria-hidden="true" tabindex="-1"></a><span class="bu">.</span></span>
-<span id="cb56-2"><a href="#cb56-2" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
-<span id="cb56-3"><a href="#cb56-3" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
-<span id="cb56-4"><a href="#cb56-4" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
-<span id="cb56-5"><a href="#cb56-5" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
-<span id="cb56-6"><a href="#cb56-6" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
-<span id="cb56-7"><a href="#cb56-7" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
-<span id="cb56-8"><a href="#cb56-8" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
-<span id="cb56-9"><a href="#cb56-9" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
-<span id="cb56-10"><a href="#cb56-10" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
-<span id="cb56-11"><a href="#cb56-11" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
-<span id="cb56-12"><a href="#cb56-12" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
-<span id="cb56-13"><a href="#cb56-13" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
-<span id="cb56-14"><a href="#cb56-14" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> backup</span>
-<span id="cb56-15"><a href="#cb56-15" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
-<span id="cb56-16"><a href="#cb56-16" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-23-calibration.txt</span>
-<span id="cb56-17"><a href="#cb56-17" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-26-calibration.txt</span>
-<span id="cb56-18"><a href="#cb56-18" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> │   └── 2015-11-23-calibration.txt</span>
-<span id="cb56-19"><a href="#cb56-19" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
-<span id="cb56-20"><a href="#cb56-20" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset1.txt</span>
-<span id="cb56-21"><a href="#cb56-21" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset2.txt</span>
-<span id="cb56-22"><a href="#cb56-22" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset_overview.txt</span>
-<span id="cb56-23"><a href="#cb56-23" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset1.txt</span>
-<span id="cb56-24"><a href="#cb56-24" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset2.txt</span>
-<span id="cb56-25"><a href="#cb56-25" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset_overview.txt</span>
-<span id="cb56-26"><a href="#cb56-26" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset1.txt</span>
-<span id="cb56-27"><a href="#cb56-27" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset2.txt</span>
-<span id="cb56-28"><a href="#cb56-28" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     └── 2015-11-23-dataset_overview.txt</span>
-<span id="cb56-29"><a href="#cb56-29" aria-hidden="true" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
-<span id="cb56-30"><a href="#cb56-30" aria-hidden="true" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
-<span id="cb56-31"><a href="#cb56-31" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset1.txt</span>
-<span id="cb56-32"><a href="#cb56-32" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset2.txt</span>
-<span id="cb56-33"><a href="#cb56-33" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset_overview.txt</span>
-<span id="cb56-34"><a href="#cb56-34" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset1.txt</span>
-<span id="cb56-35"><a href="#cb56-35" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset2.txt</span>
-<span id="cb56-36"><a href="#cb56-36" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> └── 2015-11-23-dataset_overview.txt</span>
-<span id="cb56-37"><a href="#cb56-37" aria-hidden="true" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span>
-<span id="cb56-38"><a href="#cb56-38" aria-hidden="true" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-calibration.txt</span>
-<span id="cb56-39"><a href="#cb56-39" aria-hidden="true" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
-<span id="cb56-40"><a href="#cb56-40" aria-hidden="true" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
-<span id="cb56-41"><a href="#cb56-41" aria-hidden="true" tabindex="-1"></a>        <span class="ex">└──</span> 2015-11-23-dataset_overview.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb56-1"><a href="#cb56-1" tabindex="-1"></a><span class="bu">.</span></span>
+<span id="cb56-2"><a href="#cb56-2" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
+<span id="cb56-3"><a href="#cb56-3" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
+<span id="cb56-4"><a href="#cb56-4" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
+<span id="cb56-5"><a href="#cb56-5" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
+<span id="cb56-6"><a href="#cb56-6" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
+<span id="cb56-7"><a href="#cb56-7" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
+<span id="cb56-8"><a href="#cb56-8" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
+<span id="cb56-9"><a href="#cb56-9" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
+<span id="cb56-10"><a href="#cb56-10" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
+<span id="cb56-11"><a href="#cb56-11" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
+<span id="cb56-12"><a href="#cb56-12" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
+<span id="cb56-13"><a href="#cb56-13" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
+<span id="cb56-14"><a href="#cb56-14" tabindex="-1"></a><span class="ex">├──</span> backup</span>
+<span id="cb56-15"><a href="#cb56-15" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
+<span id="cb56-16"><a href="#cb56-16" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-23-calibration.txt</span>
+<span id="cb56-17"><a href="#cb56-17" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-26-calibration.txt</span>
+<span id="cb56-18"><a href="#cb56-18" tabindex="-1"></a><span class="ex">│  </span> │   └── 2015-11-23-calibration.txt</span>
+<span id="cb56-19"><a href="#cb56-19" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
+<span id="cb56-20"><a href="#cb56-20" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset1.txt</span>
+<span id="cb56-21"><a href="#cb56-21" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset2.txt</span>
+<span id="cb56-22"><a href="#cb56-22" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset_overview.txt</span>
+<span id="cb56-23"><a href="#cb56-23" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset1.txt</span>
+<span id="cb56-24"><a href="#cb56-24" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset2.txt</span>
+<span id="cb56-25"><a href="#cb56-25" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset_overview.txt</span>
+<span id="cb56-26"><a href="#cb56-26" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset1.txt</span>
+<span id="cb56-27"><a href="#cb56-27" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset2.txt</span>
+<span id="cb56-28"><a href="#cb56-28" tabindex="-1"></a><span class="ex">│  </span>     └── 2015-11-23-dataset_overview.txt</span>
+<span id="cb56-29"><a href="#cb56-29" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
+<span id="cb56-30"><a href="#cb56-30" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
+<span id="cb56-31"><a href="#cb56-31" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset1.txt</span>
+<span id="cb56-32"><a href="#cb56-32" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset2.txt</span>
+<span id="cb56-33"><a href="#cb56-33" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset_overview.txt</span>
+<span id="cb56-34"><a href="#cb56-34" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset1.txt</span>
+<span id="cb56-35"><a href="#cb56-35" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset2.txt</span>
+<span id="cb56-36"><a href="#cb56-36" tabindex="-1"></a>    <span class="ex">│  </span> └── 2015-11-23-dataset_overview.txt</span>
+<span id="cb56-37"><a href="#cb56-37" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span>
+<span id="cb56-38"><a href="#cb56-38" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-calibration.txt</span>
+<span id="cb56-39"><a href="#cb56-39" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
+<span id="cb56-40"><a href="#cb56-40" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
+<span id="cb56-41"><a href="#cb56-41" tabindex="-1"></a>        <span class="ex">└──</span> 2015-11-23-dataset_overview.txt</span></code></pre>
 </div>
 </div>
 </div>
@@ -1316,9 +1309,9 @@ <h4 class="accordion-header" id="headingSolution8">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb57">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb57-1"><a href="#cb57-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>calibration.txt backup/calibration</span>
-<span id="cb57-2"><a href="#cb57-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp 2015-11-<span class="pp">*</span> send_to_bob/all_november_files/</span>
-<span id="cb57-3"><a href="#cb57-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>-23-dataset<span class="pp">*</span> send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb57-1"><a href="#cb57-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>calibration.txt backup/calibration</span>
+<span id="cb57-2"><a href="#cb57-2" tabindex="-1"></a><span class="ex">$</span> cp 2015-11-<span class="pp">*</span> send_to_bob/all_november_files/</span>
+<span id="cb57-3"><a href="#cb57-3" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>-23-dataset<span class="pp">*</span> send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
 </div>
 </div>
 </div>
@@ -1337,7 +1330,7 @@ <h3 class="callout-title">Organizing Directories and Files<a class="anchor" aria
 <div class="codewrapper sourceCode" id="cb58">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb58-1"><a href="#cb58-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb58-1"><a href="#cb58-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1351,7 +1344,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb60">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb60-1"><a href="#cb60-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb60-1"><a href="#cb60-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1361,7 +1354,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb62">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb62-1"><a href="#cb62-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls analyzed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb62-1"><a href="#cb62-1" tabindex="-1"></a><span class="ex">$</span> ls analyzed</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1381,7 +1374,7 @@ <h4 class="accordion-header" id="headingSolution9">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb64">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb64-1"><a href="#cb64-1" aria-hidden="true" tabindex="-1"></a><span class="fu">mv</span> <span class="pp">*</span>.dat analyzed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb64-1"><a href="#cb64-1" tabindex="-1"></a><span class="fu">mv</span> <span class="pp">*</span>.dat analyzed</span></code></pre>
 </div>
 <p>Jamie needs to move her files <code>fructose.dat</code> and
 <code>sucrose.dat</code> to the <code>analyzed</code> directory. The
@@ -1423,39 +1416,39 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb66">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb66-1"><a href="#cb66-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
-<span id="cb66-2"><a href="#cb66-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data</span>
-<span id="cb66-3"><a href="#cb66-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span>
-<span id="cb66-4"><a href="#cb66-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb66-1"><a href="#cb66-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
+<span id="cb66-2"><a href="#cb66-2" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data</span>
+<span id="cb66-3"><a href="#cb66-3" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span>
+<span id="cb66-4"><a href="#cb66-4" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb67">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb67-1"><a href="#cb67-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
-<span id="cb67-2"><a href="#cb67-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
-<span id="cb67-3"><a href="#cb67-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
-<span id="cb67-4"><a href="#cb67-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd data</span>
-<span id="cb67-5"><a href="#cb67-5" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb67-1"><a href="#cb67-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
+<span id="cb67-2"><a href="#cb67-2" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
+<span id="cb67-3"><a href="#cb67-3" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
+<span id="cb67-4"><a href="#cb67-4" tabindex="-1"></a><span class="ex">$</span> cd data</span>
+<span id="cb67-5"><a href="#cb67-5" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb68">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb68-1"><a href="#cb68-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span>
-<span id="cb68-2"><a href="#cb68-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb68-1"><a href="#cb68-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span>
+<span id="cb68-2"><a href="#cb68-2" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb69">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb69-1"><a href="#cb69-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/raw</span>
-<span id="cb69-2"><a href="#cb69-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb69-1"><a href="#cb69-1" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/raw</span>
+<span id="cb69-2"><a href="#cb69-2" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/processed</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb70">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb70-1"><a href="#cb70-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
-<span id="cb70-2"><a href="#cb70-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
-<span id="cb70-3"><a href="#cb70-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
-<span id="cb70-4"><a href="#cb70-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb70-1"><a href="#cb70-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
+<span id="cb70-2"><a href="#cb70-2" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
+<span id="cb70-3"><a href="#cb70-3" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
+<span id="cb70-4"><a href="#cb70-4" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
 </div>
 </div>
 </div>
@@ -1580,7 +1573,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/03-create.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-07-31",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/04-pipefilter.html b/04-pipefilter.html
index 65f32cb79..71bfea72a 100644
--- a/04-pipefilter.html
+++ b/04-pipefilter.html
@@ -322,7 +322,7 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -334,7 +334,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc cubane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> wc cubane.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -351,7 +351,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="pp">*</span>.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="pp">*</span>.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -371,7 +371,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -387,20 +387,19 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <p>The <code>-m</code> and <code>-w</code> options can also be used with
 the <code>wc</code> command to show only the number of characters or the
 number of words, respectively.</p>
-<div id="why-isnt-it-doing-anything" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="why-isnt-it-doing-anything" class="callout-inner">
-<h3 class="callout-title">Why Isn’t It Doing Anything?<a class="anchor" aria-label="anchor" href="#why-isnt-it-doing-anything"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="why-isnt-it-doing-anything">Why Isn’t It Doing Anything?<a class="anchor" aria-label="anchor" href="#why-isnt-it-doing-anything"></a></h3>
 <div class="callout-content">
 <p>What happens if a command is supposed to process a file, but we don’t
 give it a filename? For example, what if we type:</p>
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span></span></code></pre>
 </div>
 <p>but don’t type <code>*.pdb</code> (or anything else) after the
 command? Since it doesn’t have any filenames, <code>wc</code> assumes it
@@ -423,7 +422,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="op">&gt;</span> lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="op">&gt;</span> lengths.txt</span></code></pre>
 </div>
 <p>The greater than symbol, <code>&gt;</code>, tells the shell to
 <strong>redirect</strong> the command’s output to a file instead of
@@ -437,7 +436,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> ls lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -452,7 +451,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cat lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> cat lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -465,13 +464,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
   15  propane.pdb
  107  total</code></pre>
 </div>
-<div id="output-page-by-page" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="output-page-by-page" class="callout-inner">
-<h3 class="callout-title">Output Page by Page<a class="anchor" aria-label="anchor" href="#output-page-by-page"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="output-page-by-page">Output Page by Page<a class="anchor" aria-label="anchor" href="#output-page-by-page"></a></h3>
 <div class="callout-content">
 <p>We’ll continue to use <code>cat</code> in this lesson, for
 convenience and consistency, but it has the disadvantage that it always
@@ -547,7 +545,7 @@ <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -570,8 +568,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> sorted-lengths.txt</span>
-<span id="cb20-2"><a href="#cb20-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 sorted-lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> sorted-lengths.txt</span>
+<span id="cb20-2"><a href="#cb20-2" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 sorted-lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -583,20 +581,19 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 20, and so on. Since <code>sorted-lengths.txt</code> contains the
 lengths of our files ordered from least to greatest, the output of
 <code>head</code> must be the file with the fewest lines.</p>
-<div id="redirecting-to-the-same-file" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="redirecting-to-the-same-file" class="callout-inner">
-<h3 class="callout-title">Redirecting to the same file<a class="anchor" aria-label="anchor" href="#redirecting-to-the-same-file"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="redirecting-to-the-same-file">Redirecting to the same file<a class="anchor" aria-label="anchor" href="#redirecting-to-the-same-file"></a></h3>
 <div class="callout-content">
 <p>It’s a very bad idea to try redirecting the output of a command that
 operates on a file to the same file. For example:</p>
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> lengths.txt</span></code></pre>
 </div>
 <p>Doing something like this may give you incorrect results and/or
 delete the contents of <code>lengths.txt</code>.</p>
@@ -619,7 +616,7 @@ <h3 class="callout-title">What Does<code>&gt;&gt;</code>Mean?<a class="anchor" a
 <div class="codewrapper sourceCode" id="cb23">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo The echo command prints text</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" tabindex="-1"></a><span class="ex">$</span> echo The echo command prints text</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -631,13 +628,13 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;</span> testfile01.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;</span> testfile01.txt</span></code></pre>
 </div>
 <p>and:</p>
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;&gt;</span> testfile02.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;&gt;</span> testfile02.txt</span></code></pre>
 </div>
 <p>Hint: Try executing each command twice in a row and then examining
 the output files.</p>
@@ -680,8 +677,8 @@ <h3 class="callout-title">Appending Data<a class="anchor" aria-label="anchor" hr
 <div class="codewrapper sourceCode" id="cb27">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 3 animals.csv <span class="op">&gt;</span> animals-subset.csv</span>
-<span id="cb27-2"><a href="#cb27-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 2 animals.csv <span class="op">&gt;&gt;</span> animals-subset.csv</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 3 animals.csv <span class="op">&gt;</span> animals-subset.csv</span>
+<span id="cb27-2"><a href="#cb27-2" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 2 animals.csv <span class="op">&gt;&gt;</span> animals-subset.csv</span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li>The first three lines of <code>animals.csv</code>
 </li>
@@ -725,7 +722,7 @@ <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -749,7 +746,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -767,7 +764,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -855,7 +852,7 @@ <h3 class="callout-title">Pipe Reading Comprehension<a class="anchor" aria-label
 <div class="codewrapper sourceCode" id="cb35">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cat animals.csv <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5 <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 3 <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-r</span> <span class="op">&gt;</span> final.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" tabindex="-1"></a><span class="ex">$</span> cat animals.csv <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5 <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 3 <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-r</span> <span class="op">&gt;</span> final.txt</span></code></pre>
 </div>
 <p>Hint: build the pipeline up one command at a time to test your
 understanding</p>
@@ -897,7 +894,7 @@ <h3 class="callout-title">Pipe Construction<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv</span></code></pre>
 </div>
 <p>The <code>cut</code> command is used to remove or ‘cut out’ certain
 sections of each line in the file, and <code>cut</code> expects the
@@ -936,7 +933,7 @@ <h4 class="accordion-header" id="headingSolution6">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span></code></pre>
 </div>
 </div>
 </div>
@@ -1000,8 +997,8 @@ <h4 class="accordion-header" id="headingSolution7">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd north-pacific-gyre</span>
-<span id="cb41-2"><a href="#cb41-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="ex">$</span> cd north-pacific-gyre</span>
+<span id="cb41-2"><a href="#cb41-2" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt</span></code></pre>
 </div>
 <p>The output is 18 lines that look like this:</p>
 <div class="codewrapper">
@@ -1019,7 +1016,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1038,7 +1035,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1056,7 +1053,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="pp">*</span>Z.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="pp">*</span>Z.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1203,7 +1200,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/04-pipefilter.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2024-01-17",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/05-loop.html b/05-loop.html
index 6444dbd99..b7387bc94 100644
--- a/05-loop.html
+++ b/05-loop.html
@@ -327,7 +327,7 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 5 basilisk.dat minotaur.dat unicorn.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 5 basilisk.dat minotaur.dat unicorn.dat</span></code></pre>
 </div>
 <p>We would like to print out the classification for each species, which
 is given on the second line of each file. For each file, we would need
@@ -338,24 +338,24 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb2">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="co"># The word "for" indicates the start of a "For-loop" command</span></span>
-<span id="cb2-2"><a href="#cb2-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> thing <span class="kw">in</span> list_of_things </span>
-<span id="cb2-3"><a href="#cb2-3" aria-hidden="true" tabindex="-1"></a><span class="co">#The word "do" indicates the start of job execution list</span></span>
-<span id="cb2-4"><a href="#cb2-4" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span> </span>
-<span id="cb2-5"><a href="#cb2-5" aria-hidden="true" tabindex="-1"></a>    <span class="co"># Indentation within the loop is not required, but aids legibility</span></span>
-<span id="cb2-6"><a href="#cb2-6" aria-hidden="true" tabindex="-1"></a>    <span class="ex">operation_using/command</span> <span class="va">$thing</span> </span>
-<span id="cb2-7"><a href="#cb2-7" aria-hidden="true" tabindex="-1"></a><span class="co"># The word "done" indicates the end of a loop</span></span>
-<span id="cb2-8"><a href="#cb2-8" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span>  </span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" tabindex="-1"></a><span class="co"># The word "for" indicates the start of a "For-loop" command</span></span>
+<span id="cb2-2"><a href="#cb2-2" tabindex="-1"></a><span class="cf">for</span> thing <span class="kw">in</span> list_of_things </span>
+<span id="cb2-3"><a href="#cb2-3" tabindex="-1"></a><span class="co">#The word "do" indicates the start of job execution list</span></span>
+<span id="cb2-4"><a href="#cb2-4" tabindex="-1"></a><span class="cf">do</span> </span>
+<span id="cb2-5"><a href="#cb2-5" tabindex="-1"></a>    <span class="co"># Indentation within the loop is not required, but aids legibility</span></span>
+<span id="cb2-6"><a href="#cb2-6" tabindex="-1"></a>    <span class="ex">operation_using/command</span> <span class="va">$thing</span> </span>
+<span id="cb2-7"><a href="#cb2-7" tabindex="-1"></a><span class="co"># The word "done" indicates the end of a loop</span></span>
+<span id="cb2-8"><a href="#cb2-8" tabindex="-1"></a><span class="cf">done</span>  </span></code></pre>
 </div>
 <p>and we can apply this to our example like this:</p>
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in basilisk.dat minotaur.dat unicorn.dat</span>
-<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb3-3"><a href="#cb3-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
-<span id="cb3-4"><a href="#cb3-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
-<span id="cb3-5"><a href="#cb3-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> for filename in basilisk.dat minotaur.dat unicorn.dat</span>
+<span id="cb3-2"><a href="#cb3-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb3-3"><a href="#cb3-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
+<span id="cb3-4"><a href="#cb3-4" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
+<span id="cb3-5"><a href="#cb3-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -367,13 +367,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 unicorn.dat
 CLASSIFICATION: equus monoceros</code></pre>
 </div>
-<div id="follow-the-prompt" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="follow-the-prompt" class="callout-inner">
-<h3 class="callout-title">Follow the Prompt<a class="anchor" aria-label="anchor" href="#follow-the-prompt"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="follow-the-prompt">Follow the Prompt<a class="anchor" aria-label="anchor" href="#follow-the-prompt"></a></h3>
 <div class="callout-content">
 <p>The shell prompt changes from <code>$</code> to <code>&gt;</code> and
 back again as we were typing in our loop. The second prompt,
@@ -413,13 +412,12 @@ <h3 class="callout-title">Follow the Prompt<a class="anchor" aria-label="anchor"
 runs the <code>head</code> command on that file, and <code>tail</code>
 on the output of that. Since the list was only three items, the shell
 exits the <code>for</code> loop.</p>
-<div id="same-symbols-different-meanings" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="same-symbols-different-meanings" class="callout-inner">
-<h3 class="callout-title">Same Symbols, Different Meanings<a class="anchor" aria-label="anchor" href="#same-symbols-different-meanings"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="same-symbols-different-meanings">Same Symbols, Different Meanings<a class="anchor" aria-label="anchor" href="#same-symbols-different-meanings"></a></h3>
 <div class="callout-content">
 <p>Here we see <code>&gt;</code> being used as a shell prompt, whereas
 <code>&gt;</code> is also used to redirect output. Similarly,
@@ -444,19 +442,19 @@ <h3 class="callout-title">Same Symbols, Different Meanings<a class="anchor" aria
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for x in basilisk.dat minotaur.dat unicorn.dat</span>
-<span id="cb5-2"><a href="#cb5-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb5-3"><a href="#cb5-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$x</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
-<span id="cb5-4"><a href="#cb5-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> for x in basilisk.dat minotaur.dat unicorn.dat</span>
+<span id="cb5-2"><a href="#cb5-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb5-3"><a href="#cb5-3" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$x</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
+<span id="cb5-4"><a href="#cb5-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>or:</p>
 <div class="codewrapper sourceCode" id="cb6">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for temperature in basilisk.dat minotaur.dat unicorn.dat</span>
-<span id="cb6-2"><a href="#cb6-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb6-3"><a href="#cb6-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$temperature</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
-<span id="cb6-4"><a href="#cb6-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" tabindex="-1"></a><span class="ex">$</span> for temperature in basilisk.dat minotaur.dat unicorn.dat</span>
+<span id="cb6-2"><a href="#cb6-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb6-3"><a href="#cb6-3" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$temperature</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
+<span id="cb6-4"><a href="#cb6-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>it would work exactly the same way. <em>Don’t do this.</em> Programs
 are only useful if people can understand them, so meaningless names
@@ -487,15 +485,15 @@ <h3 class="callout-title">Write your own loop<a class="anchor" aria-label="ancho
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for loop_variable in 0 1 2 3 4 5 6 7 8 9</span>
-<span id="cb7-2"><a href="#cb7-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb7-3"><a href="#cb7-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$loop_variable</span></span>
-<span id="cb7-4"><a href="#cb7-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> for loop_variable in 0 1 2 3 4 5 6 7 8 9</span>
+<span id="cb7-2"><a href="#cb7-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb7-3"><a href="#cb7-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$loop_variable</span></span>
+<span id="cb7-4"><a href="#cb7-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -535,19 +533,19 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb10-2"><a href="#cb10-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb10-3"><a href="#cb10-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">*.pdb</span></span>
-<span id="cb10-4"><a href="#cb10-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb10-2"><a href="#cb10-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb10-3"><a href="#cb10-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">*.pdb</span></span>
+<span id="cb10-4"><a href="#cb10-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>Now, what is the output of the following code?</p>
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb11-2"><a href="#cb11-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb11-3"><a href="#cb11-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$datafile</span></span>
-<span id="cb11-4"><a href="#cb11-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb11-2"><a href="#cb11-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb11-3"><a href="#cb11-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$datafile</span></span>
+<span id="cb11-4"><a href="#cb11-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>Why do these two loops give different outputs?</p>
 </div>
@@ -558,7 +556,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>The first code block gives the same output on each iteration through
 the loop. Bash expands the wildcard <code>*.pdb</code> within the loop
@@ -568,10 +566,10 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb12">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in cubane.pdb  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
-<span id="cb12-2"><a href="#cb12-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb12-3"><a href="#cb12-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">cubane.pdb</span>  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
-<span id="cb12-4"><a href="#cb12-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" tabindex="-1"></a><span class="ex">$</span> for datafile in cubane.pdb  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
+<span id="cb12-2"><a href="#cb12-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb12-3"><a href="#cb12-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">cubane.pdb</span>  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
+<span id="cb12-4"><a href="#cb12-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -613,10 +611,10 @@ <h3 class="callout-title">Limiting Sets of Files<a class="anchor" aria-label="an
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in c<span class="pp">*</span></span>
-<span id="cb15-2"><a href="#cb15-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb15-3"><a href="#cb15-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
-<span id="cb15-4"><a href="#cb15-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> for filename in c<span class="pp">*</span></span>
+<span id="cb15-2"><a href="#cb15-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb15-3"><a href="#cb15-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
+<span id="cb15-4"><a href="#cb15-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li>No files are listed.</li>
 <li>All files are listed.</li>
@@ -631,7 +629,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so any file name starting with the letter c, followed by
@@ -652,10 +650,10 @@ <h3 class="callout-title">Limiting Sets of Files<em>(continued)</em><a class="an
 <div class="codewrapper sourceCode" id="cb16">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>c<span class="pp">*</span></span>
-<span id="cb16-2"><a href="#cb16-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb16-3"><a href="#cb16-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
-<span id="cb16-4"><a href="#cb16-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>c<span class="pp">*</span></span>
+<span id="cb16-2"><a href="#cb16-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb16-3"><a href="#cb16-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
+<span id="cb16-4"><a href="#cb16-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li>The same files would be listed.</li>
 <li>All the files are listed this time.</li>
@@ -671,7 +669,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so a file name with zero or more characters before a letter
@@ -693,11 +691,11 @@ <h3 class="callout-title">Saving to a File in a Loop - Part One<a class="anchor"
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> alkanes <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
-<span id="cb17-2"><a href="#cb17-2" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb17-3"><a href="#cb17-3" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$alkanes</span></span>
-<span id="cb17-4"><a href="#cb17-4" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$alkanes</span> <span class="op">&gt;</span> alkanes.pdb</span>
-<span id="cb17-5"><a href="#cb17-5" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="cf">for</span> alkanes <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
+<span id="cb17-2"><a href="#cb17-2" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb17-3"><a href="#cb17-3" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$alkanes</span></span>
+<span id="cb17-4"><a href="#cb17-4" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$alkanes</span> <span class="op">&gt;</span> alkanes.pdb</span>
+<span id="cb17-5"><a href="#cb17-5" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li>Prints <code>cubane.pdb</code>, <code>ethane.pdb</code>,
 <code>methane.pdb</code>, <code>octane.pdb</code>,
@@ -720,7 +718,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5">Show me the solution</h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>The text from each file in turn gets written to the
 <code>alkanes.pdb</code> file. However, the file gets overwritten on
@@ -743,10 +741,10 @@ <h3 class="callout-title">Saving to a File in a Loop - Part Two<a class="anchor"
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
-<span id="cb18-2"><a href="#cb18-2" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb18-3"><a href="#cb18-3" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
-<span id="cb18-4"><a href="#cb18-4" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
+<span id="cb18-2"><a href="#cb18-2" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb18-3"><a href="#cb18-3" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
+<span id="cb18-4"><a href="#cb18-4" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li>All of the text from <code>cubane.pdb</code>,
 <code>ethane.pdb</code>, <code>methane.pdb</code>,
@@ -772,7 +770,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution6" aria-expanded="false" aria-controls="collapseSolution6">
   <h4 class="accordion-header" id="headingSolution6">Show me the solution</h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <p>3 is the correct answer. <code>&gt;&gt;</code> appends to a file,
 rather than overwriting it with the redirected output from a command.
@@ -788,11 +786,11 @@ <h4 class="accordion-header" id="headingSolution6">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
-<span id="cb19-2"><a href="#cb19-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb19-3"><a href="#cb19-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
-<span id="cb19-4"><a href="#cb19-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
-<span id="cb19-5"><a href="#cb19-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
+<span id="cb19-2"><a href="#cb19-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb19-3"><a href="#cb19-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
+<span id="cb19-4"><a href="#cb19-4" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
+<span id="cb19-5"><a href="#cb19-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>The shell starts by expanding <code>*.dat</code> to create the list
 of files it will process. The <strong>loop body</strong> then executes
@@ -802,7 +800,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo hello there</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> echo hello there</span></code></pre>
 </div>
 <p>prints:</p>
 <div class="codewrapper">
@@ -816,11 +814,11 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
-<span id="cb22-2"><a href="#cb22-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb22-3"><a href="#cb22-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     <span class="va">$filename</span></span>
-<span id="cb22-4"><a href="#cb22-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
-<span id="cb22-5"><a href="#cb22-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
+<span id="cb22-2"><a href="#cb22-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb22-3"><a href="#cb22-3" tabindex="-1"></a><span class="op">&gt;</span>     <span class="va">$filename</span></span>
+<span id="cb22-4"><a href="#cb22-4" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
+<span id="cb22-5"><a href="#cb22-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>because then the first time through the loop, when
 <code>$filename</code> expanded to <code>basilisk.dat</code>, the shell
@@ -828,13 +826,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <code>head</code> and <code>tail</code> combination selects lines 81-100
 from whatever file is being processed (assuming the file has at least
 100 lines).</p>
-<div id="spaces-in-names" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="spaces-in-names" class="callout-inner">
-<h3 class="callout-title">Spaces in Names<a class="anchor" aria-label="anchor" href="#spaces-in-names"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="spaces-in-names">Spaces in Names<a class="anchor" aria-label="anchor" href="#spaces-in-names"></a></h3>
 <div class="callout-content">
 <p>Spaces are used to separate the elements of the list that we are
 going to loop over. If one of those elements contains a space character,
@@ -847,10 +844,10 @@ <h3 class="callout-title">Spaces in Names<a class="anchor" aria-label="anchor" h
 <div class="codewrapper sourceCode" id="cb24">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="st">"red dragon.dat"</span> <span class="st">"purple unicorn.dat"</span></span>
-<span id="cb24-2"><a href="#cb24-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb24-3"><a href="#cb24-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="st">"</span><span class="va">$filename</span><span class="st">"</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
-<span id="cb24-4"><a href="#cb24-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="st">"red dragon.dat"</span> <span class="st">"purple unicorn.dat"</span></span>
+<span id="cb24-2"><a href="#cb24-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb24-3"><a href="#cb24-3" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="st">"</span><span class="va">$filename</span><span class="st">"</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
+<span id="cb24-4"><a href="#cb24-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>It is simpler to avoid using spaces (or other special characters) in
 filenames.</p>
@@ -890,13 +887,13 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb27">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>.dat original-<span class="pp">*</span>.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>.dat original-<span class="pp">*</span>.dat</span></code></pre>
 </div>
 <p>because that would expand to:</p>
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp basilisk.dat minotaur.dat unicorn.dat original-<span class="pp">*</span>.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> cp basilisk.dat minotaur.dat unicorn.dat original-<span class="pp">*</span>.dat</span></code></pre>
 </div>
 <p>This wouldn’t back up our files, instead we get an error:</p>
 <div class="codewrapper">
@@ -913,10 +910,10 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
-<span id="cb30-2"><a href="#cb30-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb30-3"><a href="#cb30-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     cp <span class="va">$filename</span> original-<span class="va">$filename</span></span>
-<span id="cb30-4"><a href="#cb30-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
+<span id="cb30-2"><a href="#cb30-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb30-3"><a href="#cb30-3" tabindex="-1"></a><span class="op">&gt;</span>     cp <span class="va">$filename</span> original-<span class="va">$filename</span></span>
+<span id="cb30-4"><a href="#cb30-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>This loop runs the <code>cp</code> command once for each filename.
 The first time, when <code>$filename</code> expands to
@@ -924,19 +921,19 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cp</span> basilisk.dat original-basilisk.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="fu">cp</span> basilisk.dat original-basilisk.dat</span></code></pre>
 </div>
 <p>The second time, the command is:</p>
 <div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cp</span> minotaur.dat original-minotaur.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="fu">cp</span> minotaur.dat original-minotaur.dat</span></code></pre>
 </div>
 <p>The third and last time, the command is:</p>
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cp</span> unicorn.dat original-unicorn.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="fu">cp</span> unicorn.dat original-unicorn.dat</span></code></pre>
 </div>
 <p>Since the <code>cp</code> command does not normally produce any
 output, it’s hard to check that the loop is working correctly. However,
@@ -963,12 +960,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd</span>
-<span id="cb34-2"><a href="#cb34-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/north-pacific-gyre</span>
-<span id="cb34-3"><a href="#cb34-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
-<span id="cb34-4"><a href="#cb34-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb34-5"><a href="#cb34-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span></span>
-<span id="cb34-6"><a href="#cb34-6" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> cd</span>
+<span id="cb34-2"><a href="#cb34-2" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/north-pacific-gyre</span>
+<span id="cb34-3"><a href="#cb34-3" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
+<span id="cb34-4"><a href="#cb34-4" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb34-5"><a href="#cb34-5" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span></span>
+<span id="cb34-6"><a href="#cb34-6" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -987,10 +984,10 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
-<span id="cb36-2"><a href="#cb36-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb36-3"><a href="#cb36-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb36-4"><a href="#cb36-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
+<span id="cb36-2"><a href="#cb36-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb36-3"><a href="#cb36-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb36-4"><a href="#cb36-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1013,14 +1010,14 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
 </div>
 <p>Using the <kbd>←</kbd>, Nelle navigates to the <code>echo</code>
 command and changes it to <code>bash goostats.sh</code>:</p>
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
 </div>
 <p>When she presses <kbd>Enter</kbd>, the shell runs the modified
 command. However, nothing appears to happen — there is no output. After
@@ -1032,16 +1029,15 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb40">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span><span class="kw">;</span></span>
-<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a><span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span><span class="kw">;</span></span>
+<span id="cb40-2"><a href="#cb40-2" tabindex="-1"></a><span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
 </div>
-<div id="beginning-and-end" class="callout callout">
+<div id="callout4" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="beginning-and-end" class="callout-inner">
-<h3 class="callout-title">Beginning and End<a class="anchor" aria-label="anchor" href="#beginning-and-end"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="beginning-and-end">Beginning and End<a class="anchor" aria-label="anchor" href="#beginning-and-end"></a></h3>
 <div class="callout-content">
 <p>We can move to the beginning of a line in the shell by typing
 <kbd>Ctrl</kbd>+<kbd>A</kbd> and to the end using
@@ -1065,14 +1061,13 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <code>cat stats-NENE01729B.txt</code> to examine one of the output
 files. It looks good, so she decides to get some coffee and catch up on
 her reading.</p>
-<div id="those-who-know-history-can-choose-to-repeat-it" class="callout callout">
+<div id="callout5" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="those-who-know-history-can-choose-to-repeat-it" class="callout-inner">
-<h3 class="callout-title">Those Who Know History Can Choose to Repeat
-It<a class="anchor" aria-label="anchor" href="#those-who-know-history-can-choose-to-repeat-it"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="those-who-know-history-can-choose-to-repeat-it">Those Who Know History Can Choose to Repeat
+It<a class="anchor" aria-label="anchor" href="#those-who-know-history-can-choose-to-repeat-it"></a></h3>
 <div class="callout-content">
 <p>Another way to repeat previous work is to use the
 <code>history</code> command to get a list of the last few hundred
@@ -1082,7 +1077,7 @@ <h3 class="callout-title">Those Who Know History Can Choose to Repeat
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1099,13 +1094,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 </div>
 </div>
-<div id="other-history-commands" class="callout callout">
+<div id="callout6" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="other-history-commands" class="callout-inner">
-<h3 class="callout-title">Other History Commands<a class="anchor" aria-label="anchor" href="#other-history-commands"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="other-history-commands">Other History Commands<a class="anchor" aria-label="anchor" href="#other-history-commands"></a></h3>
 <div class="callout-content">
 <p>There are a number of other shortcut commands for getting at the
 history.</p>
@@ -1146,30 +1140,30 @@ <h3 class="callout-title">Doing a Dry Run<a class="anchor" aria-label="anchor" h
 <div class="codewrapper sourceCode" id="cb44">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb44-2"><a href="#cb44-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb44-3"><a href="#cb44-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     cat <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
-<span id="cb44-4"><a href="#cb44-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb44-2"><a href="#cb44-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb44-3"><a href="#cb44-3" tabindex="-1"></a><span class="op">&gt;</span>     cat <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
+<span id="cb44-4"><a href="#cb44-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>What is the difference between the two loops below, and which one
 would we want to run?</p>
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Version 1</span></span>
-<span id="cb45-2"><a href="#cb45-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb45-3"><a href="#cb45-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb45-4"><a href="#cb45-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
-<span id="cb45-5"><a href="#cb45-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="co"># Version 1</span></span>
+<span id="cb45-2"><a href="#cb45-2" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb45-3"><a href="#cb45-3" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb45-4"><a href="#cb45-4" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
+<span id="cb45-5"><a href="#cb45-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Version 2</span></span>
-<span id="cb46-2"><a href="#cb46-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb46-3"><a href="#cb46-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb46-4"><a href="#cb46-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="st">"cat </span><span class="va">$datafile</span><span class="st"> &gt;&gt; all.pdb"</span></span>
-<span id="cb46-5"><a href="#cb46-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="co"># Version 2</span></span>
+<span id="cb46-2"><a href="#cb46-2" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb46-3"><a href="#cb46-3" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb46-4"><a href="#cb46-4" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="st">"cat </span><span class="va">$datafile</span><span class="st"> &gt;&gt; all.pdb"</span></span>
+<span id="cb46-5"><a href="#cb46-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 </div>
 </div>
@@ -1179,7 +1173,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution7" aria-expanded="false" aria-controls="collapseSolution7">
   <h4 class="accordion-header" id="headingSolution7">Show me the solution</h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
 <div class="accordion-body">
 <p>The second version is the one we want to run. This prints to screen
 everything enclosed in the quote marks, expanding the loop variable name
@@ -1212,13 +1206,13 @@ <h3 class="callout-title">Nested Loops<a class="anchor" aria-label="anchor" href
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for species in cubane ethane methane</span>
-<span id="cb47-2"><a href="#cb47-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb47-3"><a href="#cb47-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     for <span class="ex">temperature</span> in 25 30 37 40</span>
-<span id="cb47-4"><a href="#cb47-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     do</span>
-<span id="cb47-5"><a href="#cb47-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>         mkdir <span class="va">$species</span><span class="ex">-</span><span class="va">$temperature</span></span>
-<span id="cb47-6"><a href="#cb47-6" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     done</span>
-<span id="cb47-7"><a href="#cb47-7" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> for species in cubane ethane methane</span>
+<span id="cb47-2"><a href="#cb47-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb47-3"><a href="#cb47-3" tabindex="-1"></a><span class="op">&gt;</span>     for <span class="ex">temperature</span> in 25 30 37 40</span>
+<span id="cb47-4"><a href="#cb47-4" tabindex="-1"></a><span class="op">&gt;</span>     do</span>
+<span id="cb47-5"><a href="#cb47-5" tabindex="-1"></a><span class="op">&gt;</span>         mkdir <span class="va">$species</span><span class="ex">-</span><span class="va">$temperature</span></span>
+<span id="cb47-6"><a href="#cb47-6" tabindex="-1"></a><span class="op">&gt;</span>     done</span>
+<span id="cb47-7"><a href="#cb47-7" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 </div>
 </div>
@@ -1228,7 +1222,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution8" aria-expanded="false" aria-controls="collapseSolution8">
   <h4 class="accordion-header" id="headingSolution8">Show me the solution</h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
 <div class="accordion-body">
 <p>We have a nested loop, i.e. contained within another loop, so for
 each species in the outer loop, the inner loop (the nested loop)
@@ -1326,7 +1320,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/05-loop.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-11-10",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/06-script.html b/06-script.html
index 1d96a08b3..384bc2c70 100644
--- a/06-script.html
+++ b/06-script.html
@@ -326,8 +326,8 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd alkanes</span>
-<span id="cb1-2"><a href="#cb1-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> cd alkanes</span>
+<span id="cb1-2"><a href="#cb1-2" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <p>The command <code>nano middle.sh</code> opens the file
 <code>middle.sh</code> within the text editor ‘nano’ (which runs within
@@ -349,7 +349,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -362,13 +362,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 <p>Sure enough, our script’s output is exactly what we would get if we
 ran that pipeline directly.</p>
-<div id="text-vs.-whatever" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="text-vs.-whatever" class="callout-inner">
-<h3 class="callout-title">Text vs. Whatever<a class="anchor" aria-label="anchor" href="#text-vs.-whatever"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="text-vs--whatever">Text vs. Whatever<a class="anchor" aria-label="anchor" href="#text-vs--whatever"></a></h3>
 <div class="callout-content">
 <p>We usually call programs like Microsoft Word or LibreOffice Writer
 “text editors”, but we need to be a bit more careful when it comes to
@@ -391,7 +390,7 @@ <h3 class="callout-title">Text vs. Whatever<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <p>Now, within “nano”, replace the text <code>octane.pdb</code> with the
 special variable called <code>$1</code>:</p>
@@ -402,7 +401,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh octane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh octane.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -417,7 +416,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -428,13 +427,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 ATOM     12  H           1      -0.048  -1.362  -0.205  1.00  0.00
 ATOM     13  H           1      -1.183   0.500  -1.412  1.00  0.00</code></pre>
 </div>
-<div id="double-quotes-around-arguments" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="double-quotes-around-arguments" class="callout-inner">
-<h3 class="callout-title">Double-Quotes Around Arguments<a class="anchor" aria-label="anchor" href="#double-quotes-around-arguments"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="double-quotes-around-arguments">Double-Quotes Around Arguments<a class="anchor" aria-label="anchor" href="#double-quotes-around-arguments"></a></h3>
 <div class="callout-content">
 <p>For the same reason that we put the loop variable inside
 double-quotes, in case the filename happens to contain any spaces, we
@@ -455,14 +453,14 @@ <h3 class="callout-title">Double-Quotes Around Arguments<a class="anchor" aria-l
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <pre class="source"><code>head -n "$2" "$1" | tail -n "$3"</code></pre>
 <p>We can now run:</p>
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 15 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 15 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -478,7 +476,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 20 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 20 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -496,7 +494,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <pre class="source"><code># Select lines from the middle of a file.
 # Usage: bash middle.sh filename end_line num_lines
@@ -513,7 +511,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
 </div>
 <p>because <code>wc -l</code> lists the number of lines in the files
 (recall that <code>wc</code> stands for ‘word count’, adding the
@@ -533,7 +531,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano sorted.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> nano sorted.sh</span></code></pre>
 </div>
 <pre class="source"><code># Sort files by their length.
 # Usage: bash sorted.sh one_or_more_filenames
@@ -541,7 +539,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash sorted.sh <span class="pp">*</span>.pdb ../creatures/<span class="pp">*</span>.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> bash sorted.sh <span class="pp">*</span>.pdb ../creatures/<span class="pp">*</span>.dat</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -599,16 +597,16 @@ <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script to find unique species in csv files where species is the second data field</span></span>
-<span id="cb25-2"><a href="#cb25-2" aria-hidden="true" tabindex="-1"></a><span class="co"># This script accepts any number of file names as command line arguments</span></span>
-<span id="cb25-3"><a href="#cb25-3" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb25-4"><a href="#cb25-4" aria-hidden="true" tabindex="-1"></a><span class="co"># Loop over all files</span></span>
-<span id="cb25-5"><a href="#cb25-5" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> file <span class="kw">in</span> <span class="va">$@</span></span>
-<span id="cb25-6"><a href="#cb25-6" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb25-7"><a href="#cb25-7" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="st">"Unique species in </span><span class="va">$file</span><span class="st">:"</span></span>
-<span id="cb25-8"><a href="#cb25-8" aria-hidden="true" tabindex="-1"></a>    <span class="co"># Extract species names</span></span>
-<span id="cb25-9"><a href="#cb25-9" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 2 <span class="va">$file</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span>
-<span id="cb25-10"><a href="#cb25-10" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="co"># Script to find unique species in csv files where species is the second data field</span></span>
+<span id="cb25-2"><a href="#cb25-2" tabindex="-1"></a><span class="co"># This script accepts any number of file names as command line arguments</span></span>
+<span id="cb25-3"><a href="#cb25-3" tabindex="-1"></a></span>
+<span id="cb25-4"><a href="#cb25-4" tabindex="-1"></a><span class="co"># Loop over all files</span></span>
+<span id="cb25-5"><a href="#cb25-5" tabindex="-1"></a><span class="cf">for</span> file <span class="kw">in</span> <span class="va">$@</span></span>
+<span id="cb25-6"><a href="#cb25-6" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb25-7"><a href="#cb25-7" tabindex="-1"></a>    <span class="bu">echo</span> <span class="st">"Unique species in </span><span class="va">$file</span><span class="st">:"</span></span>
+<span id="cb25-8"><a href="#cb25-8" tabindex="-1"></a>    <span class="co"># Extract species names</span></span>
+<span id="cb25-9"><a href="#cb25-9" tabindex="-1"></a>    <span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 2 <span class="va">$file</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span>
+<span id="cb25-10"><a href="#cb25-10" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 </div>
 </div>
@@ -622,7 +620,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> redo-figure-3.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> redo-figure-3.sh</span></code></pre>
 </div>
 <p>The file <code>redo-figure-3.sh</code> now contains:</p>
 <pre class="source"><code>297 bash goostats.sh NENE01729B.txt stats-NENE01729B.txt
@@ -647,7 +645,7 @@ <h3 class="callout-title">Why Record Commands in the History Before
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> recent.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> recent.sh</span></code></pre>
 </div>
 <p>the last command in the file is the <code>history</code> command
 itself, i.e., the shell has added <code>history</code> to the command
@@ -687,37 +685,37 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb29">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ../../north-pacific-gyre/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="ex">$</span> cd ../../north-pacific-gyre/</span></code></pre>
 </div>
 <p>She creates a file using <code>nano</code> …</p>
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano do-stats.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> nano do-stats.sh</span></code></pre>
 </div>
 <p>…which contains the following:</p>
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
-<span id="cb31-2"><a href="#cb31-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
-<span id="cb31-3"><a href="#cb31-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb31-4"><a href="#cb31-4" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
-<span id="cb31-5"><a href="#cb31-5" aria-hidden="true" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb31-6"><a href="#cb31-6" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
+<span id="cb31-2"><a href="#cb31-2" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
+<span id="cb31-3"><a href="#cb31-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb31-4"><a href="#cb31-4" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
+<span id="cb31-5"><a href="#cb31-5" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb31-6"><a href="#cb31-6" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <p>She saves this in a file called <code>do-stats.sh</code> so that she
 can now re-do the first stage of her analysis by typing:</p>
 <div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
 </div>
 <p>She can also do this:</p>
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt <span class="kw">|</span> <span class="fu">wc</span> <span class="at">-l</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt <span class="kw">|</span> <span class="fu">wc</span> <span class="at">-l</span></span></code></pre>
 </div>
 <p>so that the output is just the number of files processed rather than
 the names of the files that were processed.</p>
@@ -727,12 +725,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Calculate stats for Site A and Site B data files.</span></span>
-<span id="cb34-2"><a href="#cb34-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
-<span id="cb34-3"><a href="#cb34-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb34-4"><a href="#cb34-4" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
-<span id="cb34-5"><a href="#cb34-5" aria-hidden="true" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb34-6"><a href="#cb34-6" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="co"># Calculate stats for Site A and Site B data files.</span></span>
+<span id="cb34-2"><a href="#cb34-2" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
+<span id="cb34-3"><a href="#cb34-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb34-4"><a href="#cb34-4" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
+<span id="cb34-5"><a href="#cb34-5" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb34-6"><a href="#cb34-6" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <p>The advantage is that this always selects the right files: she
 doesn’t have to remember to exclude the ‘Z’ files. The disadvantage is
@@ -757,15 +755,15 @@ <h3 class="callout-title">Variables in Shell Scripts<a class="anchor" aria-label
 <div class="codewrapper sourceCode" id="cb35">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" aria-hidden="true" tabindex="-1"></a><span class="fu">head</span> <span class="at">-n</span> <span class="va">$2</span> <span class="va">$1</span></span>
-<span id="cb35-2"><a href="#cb35-2" aria-hidden="true" tabindex="-1"></a><span class="fu">tail</span> <span class="at">-n</span> <span class="va">$3</span> <span class="va">$1</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" tabindex="-1"></a><span class="fu">head</span> <span class="at">-n</span> <span class="va">$2</span> <span class="va">$1</span></span>
+<span id="cb35-2"><a href="#cb35-2" tabindex="-1"></a><span class="fu">tail</span> <span class="at">-n</span> <span class="va">$3</span> <span class="va">$1</span></span></code></pre>
 </div>
 <p>While you are in the <code>alkanes</code> directory, you type the
 following command:</p>
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash script.sh <span class="st">'*.pdb'</span> 1 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> bash script.sh <span class="st">'*.pdb'</span> 1 1</span></code></pre>
 </div>
 <p>Which of the following outputs would you expect to see?</p>
 <ol style="list-style-type: decimal"><li>All of the lines between the first and the last lines of each file
@@ -793,8 +791,8 @@ <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span>
-<span id="cb37-2"><a href="#cb37-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span>
+<span id="cb37-2"><a href="#cb37-2" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span></code></pre>
 </div>
 <p>The shell does not expand <code>'*.pdb'</code> because it is enclosed
 by quote marks. As such, the first argument to the script is
@@ -820,7 +818,7 @@ <h3 class="callout-title">Find the Longest File With a Given
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/alkanes pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/alkanes pdb</span></code></pre>
 </div>
 <p>would print the name of the <code>.pdb</code> file in
 <code>shell-lesson-data/exercise-data/alkanes</code> that has the most
@@ -829,7 +827,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/writing txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/writing txt</span></code></pre>
 </div>
 </div>
 </div>
@@ -844,13 +842,13 @@ <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb40">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Shell script which takes two arguments:</span></span>
-<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a><span class="co">#    1. a directory name</span></span>
-<span id="cb40-3"><a href="#cb40-3" aria-hidden="true" tabindex="-1"></a><span class="co">#    2. a file extension</span></span>
-<span id="cb40-4"><a href="#cb40-4" aria-hidden="true" tabindex="-1"></a><span class="co"># and prints the name of the file in that directory</span></span>
-<span id="cb40-5"><a href="#cb40-5" aria-hidden="true" tabindex="-1"></a><span class="co"># with the most lines which matches the file extension.</span></span>
-<span id="cb40-6"><a href="#cb40-6" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb40-7"><a href="#cb40-7" aria-hidden="true" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$1</span>/<span class="pp">*</span>.<span class="va">$2</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 2 <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" tabindex="-1"></a><span class="co"># Shell script which takes two arguments:</span></span>
+<span id="cb40-2"><a href="#cb40-2" tabindex="-1"></a><span class="co">#    1. a directory name</span></span>
+<span id="cb40-3"><a href="#cb40-3" tabindex="-1"></a><span class="co">#    2. a file extension</span></span>
+<span id="cb40-4"><a href="#cb40-4" tabindex="-1"></a><span class="co"># and prints the name of the file in that directory</span></span>
+<span id="cb40-5"><a href="#cb40-5" tabindex="-1"></a><span class="co"># with the most lines which matches the file extension.</span></span>
+<span id="cb40-6"><a href="#cb40-6" tabindex="-1"></a></span>
+<span id="cb40-7"><a href="#cb40-7" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$1</span>/<span class="pp">*</span>.<span class="va">$2</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 2 <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
 </div>
 <p>The first part of the pipeline, <code>wc -l $1/*.$2 | sort -n</code>,
 counts the lines in each file and sorts them numerically (largest last).
@@ -883,23 +881,23 @@ <h3 class="callout-title">Script Reading Comprehension<a class="anchor" aria-lab
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script 1</span></span>
-<span id="cb41-2"><a href="#cb41-2" aria-hidden="true" tabindex="-1"></a><span class="bu">echo</span> <span class="pp">*</span>.<span class="pp">*</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="co"># Script 1</span></span>
+<span id="cb41-2"><a href="#cb41-2" tabindex="-1"></a><span class="bu">echo</span> <span class="pp">*</span>.<span class="pp">*</span></span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script 2</span></span>
-<span id="cb42-2"><a href="#cb42-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> filename <span class="kw">in</span> <span class="va">$1</span> <span class="va">$2</span> <span class="va">$3</span></span>
-<span id="cb42-3"><a href="#cb42-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb42-4"><a href="#cb42-4" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$filename</span></span>
-<span id="cb42-5"><a href="#cb42-5" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="co"># Script 2</span></span>
+<span id="cb42-2"><a href="#cb42-2" tabindex="-1"></a><span class="cf">for</span> filename <span class="kw">in</span> <span class="va">$1</span> <span class="va">$2</span> <span class="va">$3</span></span>
+<span id="cb42-3"><a href="#cb42-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb42-4"><a href="#cb42-4" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$filename</span></span>
+<span id="cb42-5"><a href="#cb42-5" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script 3</span></span>
-<span id="cb43-2"><a href="#cb43-2" aria-hidden="true" tabindex="-1"></a><span class="bu">echo</span> <span class="va">$@</span>.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="co"># Script 3</span></span>
+<span id="cb43-2"><a href="#cb43-2" tabindex="-1"></a><span class="bu">echo</span> <span class="va">$@</span>.pdb</span></code></pre>
 </div>
 </div>
 </div>
@@ -947,26 +945,26 @@ <h3 class="callout-title">Debugging Scripts<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
-<span id="cb45-2"><a href="#cb45-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
-<span id="cb45-3"><a href="#cb45-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb45-4"><a href="#cb45-4" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datfile</span></span>
-<span id="cb45-5"><a href="#cb45-5" aria-hidden="true" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb45-6"><a href="#cb45-6" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
+<span id="cb45-2"><a href="#cb45-2" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
+<span id="cb45-3"><a href="#cb45-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb45-4"><a href="#cb45-4" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datfile</span></span>
+<span id="cb45-5"><a href="#cb45-5" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb45-6"><a href="#cb45-6" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <p>When you run it from the <code>north-pacific-gyre</code>
 directory:</p>
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="ex">$</span> bash do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
 </div>
 <p>the output is blank. To figure out why, re-run the script using the
 <code>-x</code> option:</p>
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash <span class="at">-x</span> do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> bash <span class="at">-x</span> do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
 </div>
 <p>What is the output showing you? Which line is responsible for the
 error?</p>
@@ -1074,7 +1072,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/06-script.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-08-05",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/07-find.html b/07-find.html
index 03ca08a8c..137218144 100644
--- a/07-find.html
+++ b/07-find.html
@@ -319,9 +319,9 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd</span>
-<span id="cb1-2"><a href="#cb1-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data/writing</span>
-<span id="cb1-3"><a href="#cb1-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cat haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> cd</span>
+<span id="cb1-2"><a href="#cb1-2" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data/writing</span>
+<span id="cb1-3"><a href="#cb1-3" tabindex="-1"></a><span class="ex">$</span> cat haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -342,7 +342,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep not haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> grep not haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -365,7 +365,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep The haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> grep The haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -384,7 +384,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> The haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> The haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -398,7 +398,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> <span class="st">"is not"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> <span class="st">"is not"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -415,7 +415,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="st">"it"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="st">"it"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -433,7 +433,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -446,7 +446,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-i</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-i</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -461,7 +461,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-v</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-v</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -484,7 +484,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-r</span> Yesterday .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-r</span> Yesterday .</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -499,7 +499,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">--help</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">--help</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -559,13 +559,12 @@ <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </div>
 </div>
 </div>
-<div id="wildcards" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="wildcards" class="callout-inner">
-<h3 class="callout-title">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="wildcards">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a></h3>
 <div class="callout-content">
 <p><code>grep</code>‘s real power doesn’t come from its options, though;
 it comes from the fact that patterns can include wildcards. (The
@@ -578,7 +577,7 @@ <h3 class="callout-title">Wildcards<a class="anchor" aria-label="anchor" href="#
 <div class="codewrapper sourceCode" id="cb24">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-E</span> <span class="st">"^.o"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-E</span> <span class="st">"^.o"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -629,13 +628,13 @@ <h3 class="callout-title">Tracking a Species<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> : <span class="at">-f</span> 2</span>
-<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span></span>
-<span id="cb28-3"><a href="#cb28-3" aria-hidden="true" tabindex="-1"></a><span class="kw">|</span></span>
-<span id="cb28-4"><a href="#cb28-4" aria-hidden="true" tabindex="-1"></a><span class="fu">grep</span> <span class="at">-w</span> <span class="va">$1</span> <span class="at">-r</span> <span class="va">$2</span></span>
-<span id="cb28-5"><a href="#cb28-5" aria-hidden="true" tabindex="-1"></a><span class="kw">|</span></span>
-<span id="cb28-6"><a href="#cb28-6" aria-hidden="true" tabindex="-1"></a><span class="va">$1</span><span class="ex">.txt</span></span>
-<span id="cb28-7"><a href="#cb28-7" aria-hidden="true" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 1,3</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> : <span class="at">-f</span> 2</span>
+<span id="cb28-2"><a href="#cb28-2" tabindex="-1"></a><span class="op">&gt;</span></span>
+<span id="cb28-3"><a href="#cb28-3" tabindex="-1"></a><span class="kw">|</span></span>
+<span id="cb28-4"><a href="#cb28-4" tabindex="-1"></a><span class="fu">grep</span> <span class="at">-w</span> <span class="va">$1</span> <span class="at">-r</span> <span class="va">$2</span></span>
+<span id="cb28-5"><a href="#cb28-5" tabindex="-1"></a><span class="kw">|</span></span>
+<span id="cb28-6"><a href="#cb28-6" tabindex="-1"></a><span class="va">$1</span><span class="ex">.txt</span></span>
+<span id="cb28-7"><a href="#cb28-7" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 1,3</span></code></pre>
 </div>
 <p>Hint: use <code>man grep</code> to look for how to grep text
 recursively in a directory and <code>man cut</code> to select more than
@@ -661,7 +660,7 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash count-species.sh bear .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> bash count-species.sh bear .</span></code></pre>
 </div>
 </div>
 </div>
@@ -761,7 +760,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> find .</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -797,7 +796,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> d</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> d</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -814,7 +813,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> f</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> f</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -837,7 +836,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb40">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="pp">*</span>.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="pp">*</span>.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -852,7 +851,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> numbers.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> numbers.txt</span></code></pre>
 </div>
 <p><code>find</code> did what we asked; we just asked for the wrong
 thing.</p>
@@ -864,7 +863,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="st">"*.txt"</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="st">"*.txt"</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -873,13 +872,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <span><span class="va">.</span><span class="op">/</span><span class="va">writing</span><span class="op">/</span><span class="va">haiku.txt</span></span>
 <span><span class="va">.</span><span class="op">/</span><span class="va">numbers.txt</span></span></code></pre>
 </div>
-<div id="listing-vs.-finding" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="listing-vs.-finding" class="callout-inner">
-<h3 class="callout-title">Listing vs. Finding<a class="anchor" aria-label="anchor" href="#listing-vs.-finding"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="listing-vs--finding">Listing vs. Finding<a class="anchor" aria-label="anchor" href="#listing-vs--finding"></a></h3>
 <div class="callout-content">
 <p><code>ls</code> and <code>find</code> can be made to do similar
 things given the right options, but under normal circumstances,
@@ -898,7 +896,7 @@ <h3 class="callout-title">Listing vs. Finding<a class="anchor" aria-label="anch
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -918,7 +916,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> ./writing/LittleWomen.txt ./writing/haiku.txt ./numbers.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> ./writing/LittleWomen.txt ./writing/haiku.txt ./numbers.txt</span></code></pre>
 </div>
 <p>which is what we wanted. This expansion is exactly what the shell
 does when it expands wildcards like <code>*</code> and <code>?</code>,
@@ -932,7 +930,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb48">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="st">"searching"</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="st">"searching"</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -982,13 +980,12 @@ <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 </div>
 </div>
 </div>
-<div id="binary-files" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="binary-files" class="callout-inner">
-<h3 class="callout-title">Binary Files<a class="anchor" aria-label="anchor" href="#binary-files"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="binary-files">Binary Files<a class="anchor" aria-label="anchor" href="#binary-files"></a></h3>
 <div class="callout-content">
 <p>We have focused exclusively on finding patterns in text files. What
 if your data is stored as images, in databases, or in some other
@@ -1033,7 +1030,7 @@ <h3 class="callout-title">
 <div class="codewrapper sourceCode" id="cb50">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" aria-hidden="true" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.dat"</span><span class="va">)</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.dat"</span><span class="va">)</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
 </div>
 </div>
 </div>
@@ -1140,7 +1137,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/07-find.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-11-09",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/404.html b/404.html
index 08ae8d560..f8096c028 100644
--- a/404.html
+++ b/404.html
@@ -319,8 +319,8 @@ <h1>Page not found</h1>
   "url": "https://swcarpentry.github.io/shell-novice/404.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/404.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-02-27",
-  "datePublished": "2024-02-27"
+  "dateModified": "2024-03-05",
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/CODE_OF_CONDUCT.html b/CODE_OF_CONDUCT.html
index 589f15704..c3019b80b 100644
--- a/CODE_OF_CONDUCT.html
+++ b/CODE_OF_CONDUCT.html
@@ -337,7 +337,7 @@ <h1>Contributor Code of Conduct</h1>
   "identifier": "https://swcarpentry.github.io/shell-novice/CODE_OF_CONDUCT.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-05-02",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/LICENSE.html b/LICENSE.html
index 5716893b8..2f5343f16 100644
--- a/LICENSE.html
+++ b/LICENSE.html
@@ -388,7 +388,7 @@ <h1>Licenses</h1>
   "identifier": "https://swcarpentry.github.io/shell-novice/LICENSE.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-05-02",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/aio.html b/aio.html
index 426ddb81d..ebd340ba2 100644
--- a/aio.html
+++ b/aio.html
@@ -407,7 +407,7 @@ <h3 id="the-shell">The Shell<a class="anchor" aria-label="anchor" href="#the-she
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span></span></code></pre>
 </div>
 <p>The shell typically uses <code>$</code> as the prompt, but may use a
 different symbol. In the examples for this lesson, we’ll show the prompt
@@ -427,7 +427,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb2">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="ex">nelle@localhost</span> $</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" tabindex="-1"></a><span class="ex">nelle@localhost</span> $</span></code></pre>
 </div>
 <p>The prompt might even include more than this. Do not worry if your
 prompt is not just a short <code>$</code>. This lesson does not depend
@@ -440,7 +440,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -448,12 +448,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <pre class="output" tabindex="0"><code>Desktop     Downloads   Movies      Pictures
 Documents   Library     Music       Public</code></pre>
 </div>
-<div id="command-not-found" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="command-not-found" class="callout-inner">
-<h3 class="callout-title">Command not found<a class="anchor" aria-label="anchor" href="#command-not-found"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="command-not-found">Command not found<a class="anchor" aria-label="anchor" href="#command-not-found"></a>
 </h3>
 <div class="callout-content">
 <p>If the shell can’t find a program whose name is the command you
@@ -461,7 +461,7 @@ <h3 class="callout-title">Command not found<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ks</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> ks</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -595,7 +595,7 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -604,12 +604,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 <p>Here, the computer’s response is <code>/Users/nelle</code>, which is
 Nelle’s <strong>home directory</strong>:</p>
-<div id="home-directory-variation" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="home-directory-variation" class="callout-inner">
-<h3 class="callout-title">Home Directory Variation<a class="anchor" aria-label="anchor" href="#home-directory-variation"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="home-directory-variation">Home Directory Variation<a class="anchor" aria-label="anchor" href="#home-directory-variation"></a>
 </h3>
 <div class="callout-content">
 <p>The home directory path will look different on different operating
@@ -649,12 +649,12 @@ <h3 class="callout-title">Home Directory Variation<a class="anchor" aria-label="
 first part of its name. Similarly, we know that <code>/Users</code> is
 stored inside the root directory <code>/</code> because its name begins
 with <code>/</code>.</p>
-<div id="slashes" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="slashes" class="callout-inner">
-<h3 class="callout-title">Slashes<a class="anchor" aria-label="anchor" href="#slashes"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="slashes">Slashes<a class="anchor" aria-label="anchor" href="#slashes"></a>
 </h3>
 <div class="callout-content">
 <p>Notice that there are two meanings for the <code>/</code> character.
@@ -680,7 +680,7 @@ <h3 class="callout-title">Slashes<a class="anchor" aria-label="anchor" href="#sl
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -707,7 +707,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -719,12 +719,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <strong>sub-directories</strong>. Any names in the output that don’t
 have a classification symbol are <strong>files</strong> in the current
 working directory.</p>
-<div id="clearing-your-terminal" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="clearing-your-terminal" class="callout-inner">
-<h3 class="callout-title">Clearing your terminal<a class="anchor" aria-label="anchor" href="#clearing-your-terminal"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="clearing-your-terminal">Clearing your terminal<a class="anchor" aria-label="anchor" href="#clearing-your-terminal"></a>
 </h3>
 <div class="callout-content">
 <p>If your screen gets too cluttered, you can clear your terminal using
@@ -748,7 +748,7 @@ <h3 id="getting-help">Getting help<a class="anchor" aria-label="anchor" href="#g
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
 </div>
 <ol start="2" style="list-style-type: decimal">
 <li>We can read its manual with <code>man</code> (available on Linux and
@@ -757,15 +757,15 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb8">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
 </div>
 <p>We’ll describe both ways next.</p>
-<div id="help-for-built-in-commands" class="callout callout">
+<div id="callout4" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="help-for-built-in-commands" class="callout-inner">
-<h3 class="callout-title">Help for built-in commands<a class="anchor" aria-label="anchor" href="#help-for-built-in-commands"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="help-for-built-in-commands">Help for built-in commands<a class="anchor" aria-label="anchor" href="#help-for-built-in-commands"></a>
 </h3>
 <div class="callout-content">
 <p>Some commands are built in to the Bash shell, rather than existing as
@@ -786,7 +786,7 @@ <h4 id="the---help-option">The <code>--help</code> option<a class="anchor" aria-
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -817,12 +817,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
   -F, --classify             append indicator (one of */=&gt;@|) to entries
 ...        ...        ...</code></pre>
 </div>
-<div id="unsupported-command-line-options" class="callout callout">
+<div id="callout5" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="unsupported-command-line-options" class="callout-inner">
-<h3 class="callout-title">Unsupported command-line options<a class="anchor" aria-label="anchor" href="#unsupported-command-line-options"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="unsupported-command-line-options">Unsupported command-line options<a class="anchor" aria-label="anchor" href="#unsupported-command-line-options"></a>
 </h3>
 <div class="callout-content">
 <p>If you try to use an option that is not supported, <code>ls</code>
@@ -830,7 +830,7 @@ <h3 class="callout-title">Unsupported command-line options<a class="anchor" aria
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-j</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-j</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -849,7 +849,7 @@ <h4 id="the-man-command">The <code>man</code> command<a class="anchor" aria-labe
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
 </div>
 <p>This command will turn your terminal into a page with a description
 of the <code>ls</code> command and its options.</p>
@@ -863,12 +863,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <kbd>Shift</kbd>+<kbd>N</kbd> (for moving backward).</p>
 <p>To <strong>quit</strong> the <code>man</code> pages, press
 <kbd>Q</kbd>.</p>
-<div id="manual-pages-on-the-web" class="callout callout">
+<div id="callout6" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="manual-pages-on-the-web" class="callout-inner">
-<h3 class="callout-title">Manual pages on the web<a class="anchor" aria-label="anchor" href="#manual-pages-on-the-web"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="manual-pages-on-the-web">Manual pages on the web<a class="anchor" aria-label="anchor" href="#manual-pages-on-the-web"></a>
 </h3>
 <div class="callout-content">
 <p>Of course, there is a third way to access help for commands:
@@ -904,7 +904,7 @@ <h3 class="callout-title">Exploring More<code>ls</code>Options<a class="anchor"
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>The <code>-l</code> option makes <code>ls</code> use a
 <strong>l</strong>ong listing format, showing not only the
@@ -940,7 +940,7 @@ <h3 class="callout-title">Listing in Reverse Chronological Order<a class="anchor
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>The most recently changed file is listed last when using
 <code>-rt</code>. This can be very useful for finding your most recent
@@ -965,7 +965,7 @@ <h3 id="exploring-other-directories">Exploring Other Directories<a class="anchor
 <div class="codewrapper sourceCode" id="cb14">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb14-1"><a href="#cb14-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb14-1"><a href="#cb14-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -996,7 +996,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb16">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop/shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop/shell-lesson-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1018,9 +1018,9 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop</span>
-<span id="cb18-2"><a href="#cb18-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span>
-<span id="cb18-3"><a href="#cb18-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> cd Desktop</span>
+<span id="cb18-2"><a href="#cb18-2" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span>
+<span id="cb18-3"><a href="#cb18-3" tabindex="-1"></a><span class="ex">$</span> cd exercise-data</span></code></pre>
 </div>
 <p>These commands will move us from our home directory into our Desktop
 directory, then into the <code>shell-lesson-data</code> directory, then
@@ -1037,7 +1037,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1047,7 +1047,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1060,7 +1060,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb23">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1077,7 +1077,7 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ..</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="ex">$</span> cd ..</span></code></pre>
 </div>
 <p><code>..</code> is a special directory name meaning “the directory
 containing this one”, or more succinctly, the <strong>parent</strong> of
@@ -1087,7 +1087,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1100,7 +1100,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> <span class="at">-a</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> <span class="at">-a</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1118,12 +1118,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <p>Note that in most command line tools, multiple options can be
 combined with a single <code>-</code> and no spaces between the options;
 <code>ls -F -a</code> is equivalent to <code>ls -Fa</code>.</p>
-<div id="other-hidden-files" class="callout callout">
+<div id="callout7" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="other-hidden-files" class="callout-inner">
-<h3 class="callout-title">Other Hidden Files<a class="anchor" aria-label="anchor" href="#other-hidden-files"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="other-hidden-files">Other Hidden Files<a class="anchor" aria-label="anchor" href="#other-hidden-files"></a>
 </h3>
 <div class="callout-content">
 <p>In addition to the hidden directories <code>..</code> and
@@ -1146,14 +1146,14 @@ <h3 class="callout-title">Other Hidden Files<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> cd</span></code></pre>
 </div>
 <p>How can you check what happened? <code>pwd</code> gives us the
 answer!</p>
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1170,7 +1170,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data</span></code></pre>
 </div>
 <p>Check that we’ve moved to the right place by running <code>pwd</code>
 and <code>ls -F</code>.</p>
@@ -1196,7 +1196,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1206,16 +1206,16 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd /Users/nelle/Desktop/shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> cd /Users/nelle/Desktop/shell-lesson-data</span></code></pre>
 </div>
 <p>Run <code>pwd</code> and <code>ls -F</code> to ensure that we’re in
 the directory we expect.</p>
-<div id="two-more-shortcuts" class="callout callout">
+<div id="callout8" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="two-more-shortcuts" class="callout-inner">
-<h3 class="callout-title">Two More Shortcuts<a class="anchor" aria-label="anchor" href="#two-more-shortcuts"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="two-more-shortcuts">Two More Shortcuts<a class="anchor" aria-label="anchor" href="#two-more-shortcuts"></a>
 </h3>
 <div class="callout-content">
 <p>The shell interprets a tilde (<code>~</code>) character at the start
@@ -1240,20 +1240,20 @@ <h3 class="callout-title">Two More Shortcuts<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span></code></pre>
 </div>
 <p>Then <code>cd</code> into the <code>exercise-data/creatures</code>
 directory</p>
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/creatures</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/creatures</span></code></pre>
 </div>
 <p>Now if you run</p>
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd <span class="at">-</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> cd <span class="at">-</span></span></code></pre>
 </div>
 <p>you’ll see you’re back in <code>~/Desktop/shell-lesson-data</code>.
 Run <code>cd -</code> again and you’re back in
@@ -1291,7 +1291,7 @@ <h3 class="callout-title">Absolute vs Relative Paths<a class="anchor" aria-label
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>No: <code>.</code> stands for the current directory.</li>
@@ -1337,7 +1337,7 @@ <h3 class="callout-title">Relative Path Resolution<a class="anchor" aria-label="
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>No: there <em>is</em> a directory <code>backup</code> in
@@ -1383,7 +1383,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5">Show me the solution</h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>No: <code>pwd</code> is not the name of a directory.</li>
@@ -1406,7 +1406,7 @@ <h4 class="accordion-header" id="headingSolution5">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
 </div>
 <figure><img src="fig/shell_command_syntax.svg" alt="General syntax of a shell command" class="figure mx-auto d-block"></figure><p><code>ls</code> is the <strong>command</strong>, with an
 <strong>option</strong> <code>-F</code> and an <strong>argument</strong>
@@ -1432,8 +1432,8 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span>
-<span id="cb42-2"><a href="#cb42-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-s</span> exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span>
+<span id="cb42-2"><a href="#cb42-2" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-s</span> exercise-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1448,7 +1448,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb44">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-S</span> exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-S</span> exercise-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1462,7 +1462,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1471,12 +1471,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 Library/              Users/
 Network/              Volumes/</code></pre>
 </div>
-<div id="when-to-use-short-or-long-options" class="callout callout">
+<div id="callout9" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="when-to-use-short-or-long-options" class="callout-inner">
-<h3 class="callout-title">When to use short or long options<a class="anchor" aria-label="anchor" href="#when-to-use-short-or-long-options"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="when-to-use-short-or-long-options">When to use short or long options<a class="anchor" aria-label="anchor" href="#when-to-use-short-or-long-options"></a>
 </h3>
 <div class="callout-content">
 <p>When options exist as both short and long options:</p>
@@ -1510,7 +1510,7 @@ <h3 id="nelles-pipeline-organizing-files">Nelle’s Pipeline: Organizing Files<a
 <div class="codewrapper sourceCode" id="cb48">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
 </div>
 <p>This command is a lot to type, but she can let the shell do most of
 the work through what is called <strong>tab completion</strong>. If she
@@ -1518,14 +1518,14 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb49">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls nor</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" tabindex="-1"></a><span class="ex">$</span> ls nor</span></code></pre>
 </div>
 <p>and then presses <kbd>Tab</kbd> (the tab key on her keyboard), the
 shell automatically completes the directory name for her:</p>
 <div class="codewrapper sourceCode" id="cb50">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
 </div>
 <p>Pressing <kbd>Tab</kbd> again does nothing, since there are multiple
 possibilities; pressing <kbd>Tab</kbd> twice brings up a list of all the
@@ -1536,15 +1536,15 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb51">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb51-1"><a href="#cb51-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/goo</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb51-1"><a href="#cb51-1" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/goo</span></code></pre>
 </div>
 <p>To see all of those files, she can press <kbd>Tab</kbd> twice
 more.</p>
 <div class="codewrapper sourceCode" id="cb52">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" aria-hidden="true" tabindex="-1"></a><span class="fu">ls</span> north-pacific-gyre/goo</span>
-<span id="cb52-2"><a href="#cb52-2" aria-hidden="true" tabindex="-1"></a><span class="ex">goodiff.sh</span>   goostats.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" tabindex="-1"></a><span class="fu">ls</span> north-pacific-gyre/goo</span>
+<span id="cb52-2"><a href="#cb52-2" tabindex="-1"></a><span class="ex">goodiff.sh</span>   goostats.sh</span></code></pre>
 </div>
 <p>This is called <strong>tab completion</strong>, and we will see it in
 many other tools as we go on.</p>
@@ -1643,7 +1643,7 @@ <h3 id="step-one-see-where-we-are-and-what-we-already-have">Step one: see where
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1655,8 +1655,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/writing/</span>
-<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/writing/</span>
+<span id="cb3-2"><a href="#cb3-2" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1672,7 +1672,7 @@ <h3 id="create-a-directory">Create a directory<a class="anchor" aria-label="anch
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> mkdir thesis</span></code></pre>
 </div>
 <p>As you might guess from its name, <code>mkdir</code> means ‘make
 directory’. Since <code>thesis</code> is a relative path (i.e., does not
@@ -1681,7 +1681,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb6">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1693,7 +1693,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb8">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> thesis</span></code></pre>
 </div>
 <p>Note that <code>mkdir</code> is not limited to creating single
 directories one at a time. The <code>-p</code> option allows
@@ -1702,7 +1702,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> ../project/data ../project/results</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> ../project/data ../project/results</span></code></pre>
 </div>
 <p>The <code>-R</code> option to the <code>ls</code> command will list
 all nested subdirectories within a directory. Let’s use
@@ -1711,7 +1711,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-FR</span> ../project</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-FR</span> ../project</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1723,12 +1723,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 
 ../project/results:</code></pre>
 </div>
-<div id="two-ways-of-doing-the-same-thing" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="two-ways-of-doing-the-same-thing" class="callout-inner">
-<h3 class="callout-title">Two ways of doing the same thing<a class="anchor" aria-label="anchor" href="#two-ways-of-doing-the-same-thing"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="two-ways-of-doing-the-same-thing">Two ways of doing the same thing<a class="anchor" aria-label="anchor" href="#two-ways-of-doing-the-same-thing"></a>
 </h3>
 <div class="callout-content">
 <p>Using the shell to create a directory is no different than using a
@@ -1740,12 +1740,12 @@ <h3 class="callout-title">Two ways of doing the same thing<a class="anchor" aria
 </div>
 </div>
 </div>
-<div id="good-names-for-files-and-directories" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="good-names-for-files-and-directories" class="callout-inner">
-<h3 class="callout-title">Good names for files and directories<a class="anchor" aria-label="anchor" href="#good-names-for-files-and-directories"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="good-names-for-files-and-directories">Good names for files and directories<a class="anchor" aria-label="anchor" href="#good-names-for-files-and-directories"></a>
 </h3>
 <div class="callout-content">
 <p>Complicated names of files and directories can make your life painful
@@ -1790,15 +1790,15 @@ <h3 id="create-a-text-file">Create a text file<a class="anchor" aria-label="anch
 <div class="codewrapper sourceCode" id="cb12">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd thesis</span>
-<span id="cb12-2"><a href="#cb12-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano draft.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" tabindex="-1"></a><span class="ex">$</span> cd thesis</span>
+<span id="cb12-2"><a href="#cb12-2" tabindex="-1"></a><span class="ex">$</span> nano draft.txt</span></code></pre>
 </div>
-<div id="which-editor" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="which-editor" class="callout-inner">
-<h3 class="callout-title">Which Editor?<a class="anchor" aria-label="anchor" href="#which-editor"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="which-editor">Which Editor?<a class="anchor" aria-label="anchor" href="#which-editor"></a>
 </h3>
 <div class="callout-content">
 <p>When we say, ‘<code>nano</code> is a text editor’ we really do mean
@@ -1831,12 +1831,12 @@ <h3 class="callout-title">Which Editor?<a class="anchor" aria-label="anchor" hre
 to accept the suggested default of <code>draft.txt</code>.</p>
 <p>Once our file is saved, we can use <kbd>Ctrl</kbd>+<kbd>X</kbd> to
 quit the editor and return to the shell.</p>
-<div id="control-ctrl-or-key" class="callout callout">
+<div id="callout4" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="control-ctrl-or-key" class="callout-inner">
-<h3 class="callout-title">Control, Ctrl, or ^ Key<a class="anchor" aria-label="anchor" href="#control-ctrl-or-key"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="control-ctrl-or-key">Control, Ctrl, or ^ Key<a class="anchor" aria-label="anchor" href="#control-ctrl-or-key"></a>
 </h3>
 <div class="callout-content">
 <p>The Control key is also called the ‘Ctrl’ key. There are various ways
@@ -1864,7 +1864,7 @@ <h3 class="callout-title">Control, Ctrl, or ^ Key<a class="anchor" aria-label="a
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1884,7 +1884,7 @@ <h3 class="callout-title">Creating Files a Different Way<a class="anchor" aria-l
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> touch my_file.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> touch my_file.txt</span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li><p>What did the <code>touch</code> command do? When you look at your
@@ -1939,17 +1939,17 @@ <h3 class="callout-title">Creating Files a Different Way<em>(continued)</em><a c
 <div class="codewrapper sourceCode" id="cb16">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm my_file.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" tabindex="-1"></a><span class="ex">$</span> rm my_file.txt</span></code></pre>
 </div>
 </div>
 </div>
 </div>
-<div id="whats-in-a-name" class="callout callout">
+<div id="callout5" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="whats-in-a-name" class="callout-inner">
-<h3 class="callout-title">What’s In A Name?<a class="anchor" aria-label="anchor" href="#whats-in-a-name"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="whats-in-a-name">What’s In A Name?<a class="anchor" aria-label="anchor" href="#whats-in-a-name"></a>
 </h3>
 <div class="callout-content">
 <p>You may have noticed that all of Nelle’s files are named ‘something
@@ -1986,7 +1986,7 @@ <h3 class="callout-title">What’s In A Name?<a class="anchor" aria-label="ancho
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data/exercise-data/writing</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data/exercise-data/writing</span></code></pre>
 </div>
 <p>In our <code>thesis</code> directory we have a file
 <code>draft.txt</code> which isn’t a particularly informative name, so
@@ -1995,7 +1995,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv thesis/draft.txt thesis/quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> mv thesis/draft.txt thesis/quotes.txt</span></code></pre>
 </div>
 <p>The first argument tells <code>mv</code> what we’re ‘moving’, while
 the second is where it’s to go. In this case, we’re moving
@@ -2006,7 +2006,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2031,7 +2031,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv thesis/quotes.txt .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">$</span> mv thesis/quotes.txt .</span></code></pre>
 </div>
 <p>The effect is to move the file from the directory it was in to the
 current working directory. <code>ls</code> now shows us that
@@ -2039,7 +2039,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2052,7 +2052,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb24">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis/quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> ls thesis/quotes.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2067,7 +2067,7 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2089,18 +2089,18 @@ <h3 class="callout-title">Moving Files to a new folder<a class="anchor" aria-lab
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span>
-<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">analyzed/</span> raw/</span>
-<span id="cb28-3"><a href="#cb28-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> analyzed</span>
-<span id="cb28-4"><a href="#cb28-4" aria-hidden="true" tabindex="-1"></a><span class="ex">fructose.dat</span> glucose.dat maltose.dat sucrose.dat</span>
-<span id="cb28-5"><a href="#cb28-5" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd analyzed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span>
+<span id="cb28-2"><a href="#cb28-2" tabindex="-1"></a> <span class="ex">analyzed/</span> raw/</span>
+<span id="cb28-3"><a href="#cb28-3" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> analyzed</span>
+<span id="cb28-4"><a href="#cb28-4" tabindex="-1"></a><span class="ex">fructose.dat</span> glucose.dat maltose.dat sucrose.dat</span>
+<span id="cb28-5"><a href="#cb28-5" tabindex="-1"></a><span class="ex">$</span> cd analyzed</span></code></pre>
 </div>
 <p>Fill in the blanks to move these files to the <code>raw/</code>
 folder (i.e. the one she forgot to put them in)</p>
 <div class="codewrapper sourceCode" id="cb29">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ____/____</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ____/____</span></code></pre>
 </div>
 </div>
 </div>
@@ -2115,7 +2115,7 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ../raw</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ../raw</span></code></pre>
 </div>
 <p>Recall that <code>..</code> refers to the parent directory (i.e. one
 above the current directory) and that <code>.</code> refers to the
@@ -2135,8 +2135,8 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp quotes.txt thesis/quotations.txt</span>
-<span id="cb31-2"><a href="#cb31-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt thesis/quotations.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="ex">$</span> cp quotes.txt thesis/quotations.txt</span>
+<span id="cb31-2"><a href="#cb31-2" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt thesis/quotations.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2148,14 +2148,14 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="at">-r</span> thesis thesis_backup</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="at">-r</span> thesis thesis_backup</span></code></pre>
 </div>
 <p>We can check the result by listing the contents of both the
 <code>thesis</code> and <code>thesis_backup</code> directory:</p>
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis thesis_backup</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> ls thesis thesis_backup</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2173,8 +2173,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp thesis thesis_backup</span>
-<span id="cb36-2"><a href="#cb36-2" aria-hidden="true" tabindex="-1"></a><span class="ex">cp:</span> <span class="at">-r</span> not specified<span class="kw">;</span> <span class="ex">omitting</span> directory <span class="st">'thesis'</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> cp thesis thesis_backup</span>
+<span id="cb36-2"><a href="#cb36-2" tabindex="-1"></a><span class="ex">cp:</span> <span class="at">-r</span> not specified<span class="kw">;</span> <span class="ex">omitting</span> directory <span class="st">'thesis'</span></span></code></pre>
 </div>
 <div id="renaming-files" class="callout challenge">
 <div class="callout-square">
@@ -2233,7 +2233,7 @@ <h3 class="callout-title">Moving and Copying<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2243,7 +2243,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2253,10 +2253,10 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir recombined</span>
-<span id="cb41-2"><a href="#cb41-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv proteins.dat recombined/</span>
-<span id="cb41-3"><a href="#cb41-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp recombined/proteins.dat ../proteins-saved.dat</span>
-<span id="cb41-4"><a href="#cb41-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="ex">$</span> mkdir recombined</span>
+<span id="cb41-2"><a href="#cb41-2" tabindex="-1"></a><span class="ex">$</span> mv proteins.dat recombined/</span>
+<span id="cb41-3"><a href="#cb41-3" tabindex="-1"></a><span class="ex">$</span> cp recombined/proteins.dat ../proteins-saved.dat</span>
+<span id="cb41-4"><a href="#cb41-4" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li><code>proteins-saved.dat recombined</code></li>
@@ -2311,25 +2311,25 @@ <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> rm quotes.txt</span></code></pre>
 </div>
 <p>We can confirm the file has gone using <code>ls</code>:</p>
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="error" tabindex="0"><code>ls: cannot access 'quotes.txt': No such file or directory</code></pre>
 </div>
-<div id="deleting-is-forever" class="callout callout">
+<div id="callout6" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="deleting-is-forever" class="callout-inner">
-<h3 class="callout-title">Deleting Is Forever<a class="anchor" aria-label="anchor" href="#deleting-is-forever"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="deleting-is-forever">Deleting Is Forever<a class="anchor" aria-label="anchor" href="#deleting-is-forever"></a>
 </h3>
 <div class="callout-content">
 <p>The Unix shell doesn’t have a trash bin that we can recover deleted
@@ -2383,7 +2383,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="ex">$</span> rm thesis</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2398,7 +2398,7 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb48">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm <span class="at">-r</span> thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" tabindex="-1"></a><span class="ex">$</span> rm <span class="at">-r</span> thesis</span></code></pre>
 </div>
 <p>Given that there is no way to retrieve files deleted using the shell,
 <code>rm -r</code> <em>should be used with great caution</em> (you might
@@ -2426,16 +2426,16 @@ <h3 class="callout-title">Copy with Multiple Filenames<a class="anchor" aria-lab
 <div class="codewrapper sourceCode" id="cb49">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir backup</span>
-<span id="cb49-2"><a href="#cb49-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp creatures/minotaur.dat creatures/unicorn.dat backup/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" tabindex="-1"></a><span class="ex">$</span> mkdir backup</span>
+<span id="cb49-2"><a href="#cb49-2" tabindex="-1"></a><span class="ex">$</span> cp creatures/minotaur.dat creatures/unicorn.dat backup/</span></code></pre>
 </div>
 <p>In the example below, what does <code>cp</code> do when given three
 or more file names?</p>
 <div class="codewrapper sourceCode" id="cb50">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd creatures</span>
-<span id="cb50-2"><a href="#cb50-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" tabindex="-1"></a><span class="ex">$</span> cd creatures</span>
+<span id="cb50-2"><a href="#cb50-2" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2445,7 +2445,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb52">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp minotaur.dat unicorn.dat basilisk.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" tabindex="-1"></a><span class="ex">$</span> cp minotaur.dat unicorn.dat basilisk.dat</span></code></pre>
 </div>
 </div>
 </div>
@@ -2475,12 +2475,12 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="section level3">
 <h3 id="using-wildcards-for-accessing-multiple-files-at-once">Using wildcards for accessing multiple files at once<a class="anchor" aria-label="anchor" href="#using-wildcards-for-accessing-multiple-files-at-once"></a>
 </h3>
-<div id="wildcards" class="callout callout">
+<div id="callout7" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="wildcards" class="callout-inner">
-<h3 class="callout-title">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="wildcards">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a>
 </h3>
 <div class="callout-content">
 <p><code>*</code> is a <strong>wildcard</strong>, which represents zero
@@ -2574,25 +2574,25 @@ <h3 class="callout-title">More on Wildcards<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb54">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb54-1"><a href="#cb54-1" aria-hidden="true" tabindex="-1"></a><span class="bu">.</span></span>
-<span id="cb54-2"><a href="#cb54-2" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
-<span id="cb54-3"><a href="#cb54-3" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
-<span id="cb54-4"><a href="#cb54-4" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
-<span id="cb54-5"><a href="#cb54-5" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
-<span id="cb54-6"><a href="#cb54-6" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
-<span id="cb54-7"><a href="#cb54-7" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
-<span id="cb54-8"><a href="#cb54-8" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
-<span id="cb54-9"><a href="#cb54-9" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
-<span id="cb54-10"><a href="#cb54-10" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
-<span id="cb54-11"><a href="#cb54-11" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
-<span id="cb54-12"><a href="#cb54-12" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
-<span id="cb54-13"><a href="#cb54-13" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
-<span id="cb54-14"><a href="#cb54-14" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> backup</span>
-<span id="cb54-15"><a href="#cb54-15" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
-<span id="cb54-16"><a href="#cb54-16" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
-<span id="cb54-17"><a href="#cb54-17" aria-hidden="true" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
-<span id="cb54-18"><a href="#cb54-18" aria-hidden="true" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
-<span id="cb54-19"><a href="#cb54-19" aria-hidden="true" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb54-1"><a href="#cb54-1" tabindex="-1"></a><span class="bu">.</span></span>
+<span id="cb54-2"><a href="#cb54-2" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
+<span id="cb54-3"><a href="#cb54-3" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
+<span id="cb54-4"><a href="#cb54-4" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
+<span id="cb54-5"><a href="#cb54-5" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
+<span id="cb54-6"><a href="#cb54-6" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
+<span id="cb54-7"><a href="#cb54-7" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
+<span id="cb54-8"><a href="#cb54-8" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
+<span id="cb54-9"><a href="#cb54-9" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
+<span id="cb54-10"><a href="#cb54-10" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
+<span id="cb54-11"><a href="#cb54-11" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
+<span id="cb54-12"><a href="#cb54-12" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
+<span id="cb54-13"><a href="#cb54-13" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
+<span id="cb54-14"><a href="#cb54-14" tabindex="-1"></a><span class="ex">├──</span> backup</span>
+<span id="cb54-15"><a href="#cb54-15" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
+<span id="cb54-16"><a href="#cb54-16" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
+<span id="cb54-17"><a href="#cb54-17" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
+<span id="cb54-18"><a href="#cb54-18" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
+<span id="cb54-19"><a href="#cb54-19" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span></code></pre>
 </div>
 <p>Before heading off to another field trip, she wants to back up her
 data and send some datasets to her colleague Bob. Sam uses the following
@@ -2600,57 +2600,57 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb55">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb55-1"><a href="#cb55-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>dataset<span class="pp">*</span> backup/datasets</span>
-<span id="cb55-2"><a href="#cb55-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp ____calibration____ backup/calibration</span>
-<span id="cb55-3"><a href="#cb55-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp 2015-____-____ send_to_bob/all_november_files/</span>
-<span id="cb55-4"><a href="#cb55-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp ____ send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb55-1"><a href="#cb55-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>dataset<span class="pp">*</span> backup/datasets</span>
+<span id="cb55-2"><a href="#cb55-2" tabindex="-1"></a><span class="ex">$</span> cp ____calibration____ backup/calibration</span>
+<span id="cb55-3"><a href="#cb55-3" tabindex="-1"></a><span class="ex">$</span> cp 2015-____-____ send_to_bob/all_november_files/</span>
+<span id="cb55-4"><a href="#cb55-4" tabindex="-1"></a><span class="ex">$</span> cp ____ send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
 </div>
 <p>Help Sam by filling in the blanks.</p>
 <p>The resulting directory structure should look like this</p>
 <div class="codewrapper sourceCode" id="cb56">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb56-1"><a href="#cb56-1" aria-hidden="true" tabindex="-1"></a><span class="bu">.</span></span>
-<span id="cb56-2"><a href="#cb56-2" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
-<span id="cb56-3"><a href="#cb56-3" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
-<span id="cb56-4"><a href="#cb56-4" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
-<span id="cb56-5"><a href="#cb56-5" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
-<span id="cb56-6"><a href="#cb56-6" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
-<span id="cb56-7"><a href="#cb56-7" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
-<span id="cb56-8"><a href="#cb56-8" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
-<span id="cb56-9"><a href="#cb56-9" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
-<span id="cb56-10"><a href="#cb56-10" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
-<span id="cb56-11"><a href="#cb56-11" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
-<span id="cb56-12"><a href="#cb56-12" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
-<span id="cb56-13"><a href="#cb56-13" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
-<span id="cb56-14"><a href="#cb56-14" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> backup</span>
-<span id="cb56-15"><a href="#cb56-15" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
-<span id="cb56-16"><a href="#cb56-16" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-23-calibration.txt</span>
-<span id="cb56-17"><a href="#cb56-17" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-26-calibration.txt</span>
-<span id="cb56-18"><a href="#cb56-18" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> │   └── 2015-11-23-calibration.txt</span>
-<span id="cb56-19"><a href="#cb56-19" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
-<span id="cb56-20"><a href="#cb56-20" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset1.txt</span>
-<span id="cb56-21"><a href="#cb56-21" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset2.txt</span>
-<span id="cb56-22"><a href="#cb56-22" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset_overview.txt</span>
-<span id="cb56-23"><a href="#cb56-23" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset1.txt</span>
-<span id="cb56-24"><a href="#cb56-24" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset2.txt</span>
-<span id="cb56-25"><a href="#cb56-25" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset_overview.txt</span>
-<span id="cb56-26"><a href="#cb56-26" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset1.txt</span>
-<span id="cb56-27"><a href="#cb56-27" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset2.txt</span>
-<span id="cb56-28"><a href="#cb56-28" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     └── 2015-11-23-dataset_overview.txt</span>
-<span id="cb56-29"><a href="#cb56-29" aria-hidden="true" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
-<span id="cb56-30"><a href="#cb56-30" aria-hidden="true" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
-<span id="cb56-31"><a href="#cb56-31" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset1.txt</span>
-<span id="cb56-32"><a href="#cb56-32" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset2.txt</span>
-<span id="cb56-33"><a href="#cb56-33" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset_overview.txt</span>
-<span id="cb56-34"><a href="#cb56-34" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset1.txt</span>
-<span id="cb56-35"><a href="#cb56-35" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset2.txt</span>
-<span id="cb56-36"><a href="#cb56-36" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> └── 2015-11-23-dataset_overview.txt</span>
-<span id="cb56-37"><a href="#cb56-37" aria-hidden="true" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span>
-<span id="cb56-38"><a href="#cb56-38" aria-hidden="true" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-calibration.txt</span>
-<span id="cb56-39"><a href="#cb56-39" aria-hidden="true" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
-<span id="cb56-40"><a href="#cb56-40" aria-hidden="true" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
-<span id="cb56-41"><a href="#cb56-41" aria-hidden="true" tabindex="-1"></a>        <span class="ex">└──</span> 2015-11-23-dataset_overview.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb56-1"><a href="#cb56-1" tabindex="-1"></a><span class="bu">.</span></span>
+<span id="cb56-2"><a href="#cb56-2" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
+<span id="cb56-3"><a href="#cb56-3" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
+<span id="cb56-4"><a href="#cb56-4" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
+<span id="cb56-5"><a href="#cb56-5" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
+<span id="cb56-6"><a href="#cb56-6" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
+<span id="cb56-7"><a href="#cb56-7" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
+<span id="cb56-8"><a href="#cb56-8" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
+<span id="cb56-9"><a href="#cb56-9" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
+<span id="cb56-10"><a href="#cb56-10" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
+<span id="cb56-11"><a href="#cb56-11" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
+<span id="cb56-12"><a href="#cb56-12" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
+<span id="cb56-13"><a href="#cb56-13" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
+<span id="cb56-14"><a href="#cb56-14" tabindex="-1"></a><span class="ex">├──</span> backup</span>
+<span id="cb56-15"><a href="#cb56-15" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
+<span id="cb56-16"><a href="#cb56-16" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-23-calibration.txt</span>
+<span id="cb56-17"><a href="#cb56-17" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-26-calibration.txt</span>
+<span id="cb56-18"><a href="#cb56-18" tabindex="-1"></a><span class="ex">│  </span> │   └── 2015-11-23-calibration.txt</span>
+<span id="cb56-19"><a href="#cb56-19" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
+<span id="cb56-20"><a href="#cb56-20" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset1.txt</span>
+<span id="cb56-21"><a href="#cb56-21" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset2.txt</span>
+<span id="cb56-22"><a href="#cb56-22" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset_overview.txt</span>
+<span id="cb56-23"><a href="#cb56-23" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset1.txt</span>
+<span id="cb56-24"><a href="#cb56-24" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset2.txt</span>
+<span id="cb56-25"><a href="#cb56-25" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset_overview.txt</span>
+<span id="cb56-26"><a href="#cb56-26" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset1.txt</span>
+<span id="cb56-27"><a href="#cb56-27" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset2.txt</span>
+<span id="cb56-28"><a href="#cb56-28" tabindex="-1"></a><span class="ex">│  </span>     └── 2015-11-23-dataset_overview.txt</span>
+<span id="cb56-29"><a href="#cb56-29" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
+<span id="cb56-30"><a href="#cb56-30" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
+<span id="cb56-31"><a href="#cb56-31" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset1.txt</span>
+<span id="cb56-32"><a href="#cb56-32" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset2.txt</span>
+<span id="cb56-33"><a href="#cb56-33" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset_overview.txt</span>
+<span id="cb56-34"><a href="#cb56-34" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset1.txt</span>
+<span id="cb56-35"><a href="#cb56-35" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset2.txt</span>
+<span id="cb56-36"><a href="#cb56-36" tabindex="-1"></a>    <span class="ex">│  </span> └── 2015-11-23-dataset_overview.txt</span>
+<span id="cb56-37"><a href="#cb56-37" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span>
+<span id="cb56-38"><a href="#cb56-38" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-calibration.txt</span>
+<span id="cb56-39"><a href="#cb56-39" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
+<span id="cb56-40"><a href="#cb56-40" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
+<span id="cb56-41"><a href="#cb56-41" tabindex="-1"></a>        <span class="ex">└──</span> 2015-11-23-dataset_overview.txt</span></code></pre>
 </div>
 </div>
 </div>
@@ -2665,9 +2665,9 @@ <h4 class="accordion-header" id="headingSolution8">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb57">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb57-1"><a href="#cb57-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>calibration.txt backup/calibration</span>
-<span id="cb57-2"><a href="#cb57-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp 2015-11-<span class="pp">*</span> send_to_bob/all_november_files/</span>
-<span id="cb57-3"><a href="#cb57-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>-23-dataset<span class="pp">*</span> send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb57-1"><a href="#cb57-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>calibration.txt backup/calibration</span>
+<span id="cb57-2"><a href="#cb57-2" tabindex="-1"></a><span class="ex">$</span> cp 2015-11-<span class="pp">*</span> send_to_bob/all_november_files/</span>
+<span id="cb57-3"><a href="#cb57-3" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>-23-dataset<span class="pp">*</span> send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
 </div>
 </div>
 </div>
@@ -2686,7 +2686,7 @@ <h3 class="callout-title">Organizing Directories and Files<a class="anchor" aria
 <div class="codewrapper sourceCode" id="cb58">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb58-1"><a href="#cb58-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb58-1"><a href="#cb58-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2700,7 +2700,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb60">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb60-1"><a href="#cb60-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb60-1"><a href="#cb60-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2710,7 +2710,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb62">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb62-1"><a href="#cb62-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls analyzed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb62-1"><a href="#cb62-1" tabindex="-1"></a><span class="ex">$</span> ls analyzed</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2730,7 +2730,7 @@ <h4 class="accordion-header" id="headingSolution9">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb64">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb64-1"><a href="#cb64-1" aria-hidden="true" tabindex="-1"></a><span class="fu">mv</span> <span class="pp">*</span>.dat analyzed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb64-1"><a href="#cb64-1" tabindex="-1"></a><span class="fu">mv</span> <span class="pp">*</span>.dat analyzed</span></code></pre>
 </div>
 <p>Jamie needs to move her files <code>fructose.dat</code> and
 <code>sucrose.dat</code> to the <code>analyzed</code> directory. The
@@ -2772,39 +2772,39 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb66">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb66-1"><a href="#cb66-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
-<span id="cb66-2"><a href="#cb66-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data</span>
-<span id="cb66-3"><a href="#cb66-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span>
-<span id="cb66-4"><a href="#cb66-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb66-1"><a href="#cb66-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
+<span id="cb66-2"><a href="#cb66-2" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data</span>
+<span id="cb66-3"><a href="#cb66-3" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span>
+<span id="cb66-4"><a href="#cb66-4" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb67">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb67-1"><a href="#cb67-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
-<span id="cb67-2"><a href="#cb67-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
-<span id="cb67-3"><a href="#cb67-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
-<span id="cb67-4"><a href="#cb67-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd data</span>
-<span id="cb67-5"><a href="#cb67-5" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb67-1"><a href="#cb67-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
+<span id="cb67-2"><a href="#cb67-2" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
+<span id="cb67-3"><a href="#cb67-3" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
+<span id="cb67-4"><a href="#cb67-4" tabindex="-1"></a><span class="ex">$</span> cd data</span>
+<span id="cb67-5"><a href="#cb67-5" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb68">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb68-1"><a href="#cb68-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span>
-<span id="cb68-2"><a href="#cb68-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb68-1"><a href="#cb68-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span>
+<span id="cb68-2"><a href="#cb68-2" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb69">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb69-1"><a href="#cb69-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/raw</span>
-<span id="cb69-2"><a href="#cb69-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb69-1"><a href="#cb69-1" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/raw</span>
+<span id="cb69-2"><a href="#cb69-2" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/processed</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb70">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb70-1"><a href="#cb70-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
-<span id="cb70-2"><a href="#cb70-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
-<span id="cb70-3"><a href="#cb70-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
-<span id="cb70-4"><a href="#cb70-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb70-1"><a href="#cb70-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
+<span id="cb70-2"><a href="#cb70-2" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
+<span id="cb70-3"><a href="#cb70-3" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
+<span id="cb70-4"><a href="#cb70-4" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
 </div>
 </div>
 </div>
@@ -2921,7 +2921,7 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2933,7 +2933,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc cubane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> wc cubane.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2950,7 +2950,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="pp">*</span>.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="pp">*</span>.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2970,7 +2970,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2986,12 +2986,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <p>The <code>-m</code> and <code>-w</code> options can also be used with
 the <code>wc</code> command to show only the number of characters or the
 number of words, respectively.</p>
-<div id="why-isnt-it-doing-anything" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="why-isnt-it-doing-anything" class="callout-inner">
-<h3 class="callout-title">Why Isn’t It Doing Anything?<a class="anchor" aria-label="anchor" href="#why-isnt-it-doing-anything"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="why-isnt-it-doing-anything">Why Isn’t It Doing Anything?<a class="anchor" aria-label="anchor" href="#why-isnt-it-doing-anything"></a>
 </h3>
 <div class="callout-content">
 <p>What happens if a command is supposed to process a file, but we don’t
@@ -2999,7 +2999,7 @@ <h3 class="callout-title">Why Isn’t It Doing Anything?<a class="anchor" aria-l
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span></span></code></pre>
 </div>
 <p>but don’t type <code>*.pdb</code> (or anything else) after the
 command? Since it doesn’t have any filenames, <code>wc</code> assumes it
@@ -3023,7 +3023,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="op">&gt;</span> lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="op">&gt;</span> lengths.txt</span></code></pre>
 </div>
 <p>The greater than symbol, <code>&gt;</code>, tells the shell to
 <strong>redirect</strong> the command’s output to a file instead of
@@ -3037,7 +3037,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> ls lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3052,7 +3052,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cat lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> cat lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3065,12 +3065,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
   15  propane.pdb
  107  total</code></pre>
 </div>
-<div id="output-page-by-page" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="output-page-by-page" class="callout-inner">
-<h3 class="callout-title">Output Page by Page<a class="anchor" aria-label="anchor" href="#output-page-by-page"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="output-page-by-page">Output Page by Page<a class="anchor" aria-label="anchor" href="#output-page-by-page"></a>
 </h3>
 <div class="callout-content">
 <p>We’ll continue to use <code>cat</code> in this lesson, for
@@ -3148,7 +3148,7 @@ <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3171,8 +3171,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> sorted-lengths.txt</span>
-<span id="cb20-2"><a href="#cb20-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 sorted-lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> sorted-lengths.txt</span>
+<span id="cb20-2"><a href="#cb20-2" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 sorted-lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3184,12 +3184,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 20, and so on. Since <code>sorted-lengths.txt</code> contains the
 lengths of our files ordered from least to greatest, the output of
 <code>head</code> must be the file with the fewest lines.</p>
-<div id="redirecting-to-the-same-file" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="redirecting-to-the-same-file" class="callout-inner">
-<h3 class="callout-title">Redirecting to the same file<a class="anchor" aria-label="anchor" href="#redirecting-to-the-same-file"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="redirecting-to-the-same-file">Redirecting to the same file<a class="anchor" aria-label="anchor" href="#redirecting-to-the-same-file"></a>
 </h3>
 <div class="callout-content">
 <p>It’s a very bad idea to try redirecting the output of a command that
@@ -3197,7 +3197,7 @@ <h3 class="callout-title">Redirecting to the same file<a class="anchor" aria-lab
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> lengths.txt</span></code></pre>
 </div>
 <p>Doing something like this may give you incorrect results and/or
 delete the contents of <code>lengths.txt</code>.</p>
@@ -3220,7 +3220,7 @@ <h3 class="callout-title">What Does<code>&gt;&gt;</code>Mean?<a class="anchor" a
 <div class="codewrapper sourceCode" id="cb23">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo The echo command prints text</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" tabindex="-1"></a><span class="ex">$</span> echo The echo command prints text</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3232,13 +3232,13 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;</span> testfile01.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;</span> testfile01.txt</span></code></pre>
 </div>
 <p>and:</p>
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;&gt;</span> testfile02.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;&gt;</span> testfile02.txt</span></code></pre>
 </div>
 <p>Hint: Try executing each command twice in a row and then examining
 the output files.</p>
@@ -3281,8 +3281,8 @@ <h3 class="callout-title">Appending Data<a class="anchor" aria-label="anchor" hr
 <div class="codewrapper sourceCode" id="cb27">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 3 animals.csv <span class="op">&gt;</span> animals-subset.csv</span>
-<span id="cb27-2"><a href="#cb27-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 2 animals.csv <span class="op">&gt;&gt;</span> animals-subset.csv</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 3 animals.csv <span class="op">&gt;</span> animals-subset.csv</span>
+<span id="cb27-2"><a href="#cb27-2" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 2 animals.csv <span class="op">&gt;&gt;</span> animals-subset.csv</span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li>The first three lines of <code>animals.csv</code>
@@ -3329,7 +3329,7 @@ <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3354,7 +3354,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3372,7 +3372,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3463,7 +3463,7 @@ <h3 class="callout-title">Pipe Reading Comprehension<a class="anchor" aria-label
 <div class="codewrapper sourceCode" id="cb35">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cat animals.csv <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5 <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 3 <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-r</span> <span class="op">&gt;</span> final.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" tabindex="-1"></a><span class="ex">$</span> cat animals.csv <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5 <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 3 <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-r</span> <span class="op">&gt;</span> final.txt</span></code></pre>
 </div>
 <p>Hint: build the pipeline up one command at a time to test your
 understanding</p>
@@ -3505,7 +3505,7 @@ <h3 class="callout-title">Pipe Construction<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv</span></code></pre>
 </div>
 <p>The <code>cut</code> command is used to remove or ‘cut out’ certain
 sections of each line in the file, and <code>cut</code> expects the
@@ -3544,7 +3544,7 @@ <h4 class="accordion-header" id="headingSolution6">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span></code></pre>
 </div>
 </div>
 </div>
@@ -3611,8 +3611,8 @@ <h4 class="accordion-header" id="headingSolution7">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd north-pacific-gyre</span>
-<span id="cb41-2"><a href="#cb41-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="ex">$</span> cd north-pacific-gyre</span>
+<span id="cb41-2"><a href="#cb41-2" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt</span></code></pre>
 </div>
 <p>The output is 18 lines that look like this:</p>
 <div class="codewrapper">
@@ -3630,7 +3630,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3649,7 +3649,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3667,7 +3667,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="pp">*</span>Z.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="pp">*</span>Z.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3820,7 +3820,7 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 5 basilisk.dat minotaur.dat unicorn.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 5 basilisk.dat minotaur.dat unicorn.dat</span></code></pre>
 </div>
 <p>We would like to print out the classification for each species, which
 is given on the second line of each file. For each file, we would need
@@ -3831,24 +3831,24 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb2">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="co"># The word "for" indicates the start of a "For-loop" command</span></span>
-<span id="cb2-2"><a href="#cb2-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> thing <span class="kw">in</span> list_of_things </span>
-<span id="cb2-3"><a href="#cb2-3" aria-hidden="true" tabindex="-1"></a><span class="co">#The word "do" indicates the start of job execution list</span></span>
-<span id="cb2-4"><a href="#cb2-4" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span> </span>
-<span id="cb2-5"><a href="#cb2-5" aria-hidden="true" tabindex="-1"></a>    <span class="co"># Indentation within the loop is not required, but aids legibility</span></span>
-<span id="cb2-6"><a href="#cb2-6" aria-hidden="true" tabindex="-1"></a>    <span class="ex">operation_using/command</span> <span class="va">$thing</span> </span>
-<span id="cb2-7"><a href="#cb2-7" aria-hidden="true" tabindex="-1"></a><span class="co"># The word "done" indicates the end of a loop</span></span>
-<span id="cb2-8"><a href="#cb2-8" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span>  </span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" tabindex="-1"></a><span class="co"># The word "for" indicates the start of a "For-loop" command</span></span>
+<span id="cb2-2"><a href="#cb2-2" tabindex="-1"></a><span class="cf">for</span> thing <span class="kw">in</span> list_of_things </span>
+<span id="cb2-3"><a href="#cb2-3" tabindex="-1"></a><span class="co">#The word "do" indicates the start of job execution list</span></span>
+<span id="cb2-4"><a href="#cb2-4" tabindex="-1"></a><span class="cf">do</span> </span>
+<span id="cb2-5"><a href="#cb2-5" tabindex="-1"></a>    <span class="co"># Indentation within the loop is not required, but aids legibility</span></span>
+<span id="cb2-6"><a href="#cb2-6" tabindex="-1"></a>    <span class="ex">operation_using/command</span> <span class="va">$thing</span> </span>
+<span id="cb2-7"><a href="#cb2-7" tabindex="-1"></a><span class="co"># The word "done" indicates the end of a loop</span></span>
+<span id="cb2-8"><a href="#cb2-8" tabindex="-1"></a><span class="cf">done</span>  </span></code></pre>
 </div>
 <p>and we can apply this to our example like this:</p>
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in basilisk.dat minotaur.dat unicorn.dat</span>
-<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb3-3"><a href="#cb3-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
-<span id="cb3-4"><a href="#cb3-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
-<span id="cb3-5"><a href="#cb3-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> for filename in basilisk.dat minotaur.dat unicorn.dat</span>
+<span id="cb3-2"><a href="#cb3-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb3-3"><a href="#cb3-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
+<span id="cb3-4"><a href="#cb3-4" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
+<span id="cb3-5"><a href="#cb3-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3860,12 +3860,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 unicorn.dat
 CLASSIFICATION: equus monoceros</code></pre>
 </div>
-<div id="follow-the-prompt" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="follow-the-prompt" class="callout-inner">
-<h3 class="callout-title">Follow the Prompt<a class="anchor" aria-label="anchor" href="#follow-the-prompt"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="follow-the-prompt">Follow the Prompt<a class="anchor" aria-label="anchor" href="#follow-the-prompt"></a>
 </h3>
 <div class="callout-content">
 <p>The shell prompt changes from <code>$</code> to <code>&gt;</code> and
@@ -3906,12 +3906,12 @@ <h3 class="callout-title">Follow the Prompt<a class="anchor" aria-label="anchor"
 runs the <code>head</code> command on that file, and <code>tail</code>
 on the output of that. Since the list was only three items, the shell
 exits the <code>for</code> loop.</p>
-<div id="same-symbols-different-meanings" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="same-symbols-different-meanings" class="callout-inner">
-<h3 class="callout-title">Same Symbols, Different Meanings<a class="anchor" aria-label="anchor" href="#same-symbols-different-meanings"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="same-symbols-different-meanings">Same Symbols, Different Meanings<a class="anchor" aria-label="anchor" href="#same-symbols-different-meanings"></a>
 </h3>
 <div class="callout-content">
 <p>Here we see <code>&gt;</code> being used as a shell prompt, whereas
@@ -3937,19 +3937,19 @@ <h3 class="callout-title">Same Symbols, Different Meanings<a class="anchor" aria
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for x in basilisk.dat minotaur.dat unicorn.dat</span>
-<span id="cb5-2"><a href="#cb5-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb5-3"><a href="#cb5-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$x</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
-<span id="cb5-4"><a href="#cb5-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> for x in basilisk.dat minotaur.dat unicorn.dat</span>
+<span id="cb5-2"><a href="#cb5-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb5-3"><a href="#cb5-3" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$x</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
+<span id="cb5-4"><a href="#cb5-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>or:</p>
 <div class="codewrapper sourceCode" id="cb6">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for temperature in basilisk.dat minotaur.dat unicorn.dat</span>
-<span id="cb6-2"><a href="#cb6-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb6-3"><a href="#cb6-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$temperature</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
-<span id="cb6-4"><a href="#cb6-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" tabindex="-1"></a><span class="ex">$</span> for temperature in basilisk.dat minotaur.dat unicorn.dat</span>
+<span id="cb6-2"><a href="#cb6-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb6-3"><a href="#cb6-3" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$temperature</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
+<span id="cb6-4"><a href="#cb6-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>it would work exactly the same way. <em>Don’t do this.</em> Programs
 are only useful if people can understand them, so meaningless names
@@ -3980,15 +3980,15 @@ <h3 class="callout-title">Write your own loop<a class="anchor" aria-label="ancho
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for loop_variable in 0 1 2 3 4 5 6 7 8 9</span>
-<span id="cb7-2"><a href="#cb7-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb7-3"><a href="#cb7-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$loop_variable</span></span>
-<span id="cb7-4"><a href="#cb7-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> for loop_variable in 0 1 2 3 4 5 6 7 8 9</span>
+<span id="cb7-2"><a href="#cb7-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb7-3"><a href="#cb7-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$loop_variable</span></span>
+<span id="cb7-4"><a href="#cb7-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4028,19 +4028,19 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb10-2"><a href="#cb10-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb10-3"><a href="#cb10-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">*.pdb</span></span>
-<span id="cb10-4"><a href="#cb10-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb10-2"><a href="#cb10-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb10-3"><a href="#cb10-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">*.pdb</span></span>
+<span id="cb10-4"><a href="#cb10-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>Now, what is the output of the following code?</p>
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb11-2"><a href="#cb11-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb11-3"><a href="#cb11-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$datafile</span></span>
-<span id="cb11-4"><a href="#cb11-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb11-2"><a href="#cb11-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb11-3"><a href="#cb11-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$datafile</span></span>
+<span id="cb11-4"><a href="#cb11-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>Why do these two loops give different outputs?</p>
 </div>
@@ -4051,7 +4051,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>The first code block gives the same output on each iteration through
 the loop. Bash expands the wildcard <code>*.pdb</code> within the loop
@@ -4061,10 +4061,10 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb12">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in cubane.pdb  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
-<span id="cb12-2"><a href="#cb12-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb12-3"><a href="#cb12-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">cubane.pdb</span>  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
-<span id="cb12-4"><a href="#cb12-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" tabindex="-1"></a><span class="ex">$</span> for datafile in cubane.pdb  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
+<span id="cb12-2"><a href="#cb12-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb12-3"><a href="#cb12-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">cubane.pdb</span>  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
+<span id="cb12-4"><a href="#cb12-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4106,10 +4106,10 @@ <h3 class="callout-title">Limiting Sets of Files<a class="anchor" aria-label="an
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in c<span class="pp">*</span></span>
-<span id="cb15-2"><a href="#cb15-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb15-3"><a href="#cb15-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
-<span id="cb15-4"><a href="#cb15-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> for filename in c<span class="pp">*</span></span>
+<span id="cb15-2"><a href="#cb15-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb15-3"><a href="#cb15-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
+<span id="cb15-4"><a href="#cb15-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li>No files are listed.</li>
@@ -4126,7 +4126,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so any file name starting with the letter c, followed by
@@ -4147,10 +4147,10 @@ <h3 class="callout-title">Limiting Sets of Files<em>(continued)</em><a class="an
 <div class="codewrapper sourceCode" id="cb16">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>c<span class="pp">*</span></span>
-<span id="cb16-2"><a href="#cb16-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb16-3"><a href="#cb16-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
-<span id="cb16-4"><a href="#cb16-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>c<span class="pp">*</span></span>
+<span id="cb16-2"><a href="#cb16-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb16-3"><a href="#cb16-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
+<span id="cb16-4"><a href="#cb16-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li>The same files would be listed.</li>
@@ -4168,7 +4168,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so a file name with zero or more characters before a letter
@@ -4190,11 +4190,11 @@ <h3 class="callout-title">Saving to a File in a Loop - Part One<a class="anchor"
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> alkanes <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
-<span id="cb17-2"><a href="#cb17-2" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb17-3"><a href="#cb17-3" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$alkanes</span></span>
-<span id="cb17-4"><a href="#cb17-4" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$alkanes</span> <span class="op">&gt;</span> alkanes.pdb</span>
-<span id="cb17-5"><a href="#cb17-5" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="cf">for</span> alkanes <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
+<span id="cb17-2"><a href="#cb17-2" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb17-3"><a href="#cb17-3" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$alkanes</span></span>
+<span id="cb17-4"><a href="#cb17-4" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$alkanes</span> <span class="op">&gt;</span> alkanes.pdb</span>
+<span id="cb17-5"><a href="#cb17-5" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li>Prints <code>cubane.pdb</code>, <code>ethane.pdb</code>,
@@ -4219,7 +4219,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5">Show me the solution</h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>The text from each file in turn gets written to the
@@ -4244,10 +4244,10 @@ <h3 class="callout-title">Saving to a File in a Loop - Part Two<a class="anchor"
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
-<span id="cb18-2"><a href="#cb18-2" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb18-3"><a href="#cb18-3" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
-<span id="cb18-4"><a href="#cb18-4" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
+<span id="cb18-2"><a href="#cb18-2" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb18-3"><a href="#cb18-3" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
+<span id="cb18-4"><a href="#cb18-4" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li>All of the text from <code>cubane.pdb</code>,
@@ -4275,7 +4275,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution6" aria-expanded="false" aria-controls="collapseSolution6">
   <h4 class="accordion-header" id="headingSolution6">Show me the solution</h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <p>3 is the correct answer. <code>&gt;&gt;</code> appends to a file,
 rather than overwriting it with the redirected output from a command.
@@ -4291,11 +4291,11 @@ <h4 class="accordion-header" id="headingSolution6">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
-<span id="cb19-2"><a href="#cb19-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb19-3"><a href="#cb19-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
-<span id="cb19-4"><a href="#cb19-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
-<span id="cb19-5"><a href="#cb19-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
+<span id="cb19-2"><a href="#cb19-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb19-3"><a href="#cb19-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
+<span id="cb19-4"><a href="#cb19-4" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
+<span id="cb19-5"><a href="#cb19-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>The shell starts by expanding <code>*.dat</code> to create the list
 of files it will process. The <strong>loop body</strong> then executes
@@ -4305,7 +4305,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo hello there</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> echo hello there</span></code></pre>
 </div>
 <p>prints:</p>
 <div class="codewrapper">
@@ -4319,11 +4319,11 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
-<span id="cb22-2"><a href="#cb22-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb22-3"><a href="#cb22-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     <span class="va">$filename</span></span>
-<span id="cb22-4"><a href="#cb22-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
-<span id="cb22-5"><a href="#cb22-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
+<span id="cb22-2"><a href="#cb22-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb22-3"><a href="#cb22-3" tabindex="-1"></a><span class="op">&gt;</span>     <span class="va">$filename</span></span>
+<span id="cb22-4"><a href="#cb22-4" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
+<span id="cb22-5"><a href="#cb22-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>because then the first time through the loop, when
 <code>$filename</code> expanded to <code>basilisk.dat</code>, the shell
@@ -4331,12 +4331,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <code>head</code> and <code>tail</code> combination selects lines 81-100
 from whatever file is being processed (assuming the file has at least
 100 lines).</p>
-<div id="spaces-in-names" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="spaces-in-names" class="callout-inner">
-<h3 class="callout-title">Spaces in Names<a class="anchor" aria-label="anchor" href="#spaces-in-names"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="spaces-in-names">Spaces in Names<a class="anchor" aria-label="anchor" href="#spaces-in-names"></a>
 </h3>
 <div class="callout-content">
 <p>Spaces are used to separate the elements of the list that we are
@@ -4350,10 +4350,10 @@ <h3 class="callout-title">Spaces in Names<a class="anchor" aria-label="anchor" h
 <div class="codewrapper sourceCode" id="cb24">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="st">"red dragon.dat"</span> <span class="st">"purple unicorn.dat"</span></span>
-<span id="cb24-2"><a href="#cb24-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb24-3"><a href="#cb24-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="st">"</span><span class="va">$filename</span><span class="st">"</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
-<span id="cb24-4"><a href="#cb24-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="st">"red dragon.dat"</span> <span class="st">"purple unicorn.dat"</span></span>
+<span id="cb24-2"><a href="#cb24-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb24-3"><a href="#cb24-3" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="st">"</span><span class="va">$filename</span><span class="st">"</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
+<span id="cb24-4"><a href="#cb24-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>It is simpler to avoid using spaces (or other special characters) in
 filenames.</p>
@@ -4393,13 +4393,13 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb27">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>.dat original-<span class="pp">*</span>.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>.dat original-<span class="pp">*</span>.dat</span></code></pre>
 </div>
 <p>because that would expand to:</p>
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp basilisk.dat minotaur.dat unicorn.dat original-<span class="pp">*</span>.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> cp basilisk.dat minotaur.dat unicorn.dat original-<span class="pp">*</span>.dat</span></code></pre>
 </div>
 <p>This wouldn’t back up our files, instead we get an error:</p>
 <div class="codewrapper">
@@ -4416,10 +4416,10 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
-<span id="cb30-2"><a href="#cb30-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb30-3"><a href="#cb30-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     cp <span class="va">$filename</span> original-<span class="va">$filename</span></span>
-<span id="cb30-4"><a href="#cb30-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
+<span id="cb30-2"><a href="#cb30-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb30-3"><a href="#cb30-3" tabindex="-1"></a><span class="op">&gt;</span>     cp <span class="va">$filename</span> original-<span class="va">$filename</span></span>
+<span id="cb30-4"><a href="#cb30-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>This loop runs the <code>cp</code> command once for each filename.
 The first time, when <code>$filename</code> expands to
@@ -4427,19 +4427,19 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cp</span> basilisk.dat original-basilisk.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="fu">cp</span> basilisk.dat original-basilisk.dat</span></code></pre>
 </div>
 <p>The second time, the command is:</p>
 <div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cp</span> minotaur.dat original-minotaur.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="fu">cp</span> minotaur.dat original-minotaur.dat</span></code></pre>
 </div>
 <p>The third and last time, the command is:</p>
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cp</span> unicorn.dat original-unicorn.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="fu">cp</span> unicorn.dat original-unicorn.dat</span></code></pre>
 </div>
 <p>Since the <code>cp</code> command does not normally produce any
 output, it’s hard to check that the loop is working correctly. However,
@@ -4469,12 +4469,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd</span>
-<span id="cb34-2"><a href="#cb34-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/north-pacific-gyre</span>
-<span id="cb34-3"><a href="#cb34-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
-<span id="cb34-4"><a href="#cb34-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb34-5"><a href="#cb34-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span></span>
-<span id="cb34-6"><a href="#cb34-6" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> cd</span>
+<span id="cb34-2"><a href="#cb34-2" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/north-pacific-gyre</span>
+<span id="cb34-3"><a href="#cb34-3" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
+<span id="cb34-4"><a href="#cb34-4" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb34-5"><a href="#cb34-5" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span></span>
+<span id="cb34-6"><a href="#cb34-6" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4493,10 +4493,10 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
-<span id="cb36-2"><a href="#cb36-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb36-3"><a href="#cb36-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb36-4"><a href="#cb36-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
+<span id="cb36-2"><a href="#cb36-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb36-3"><a href="#cb36-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb36-4"><a href="#cb36-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4519,14 +4519,14 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
 </div>
 <p>Using the <kbd>←</kbd>, Nelle navigates to the <code>echo</code>
 command and changes it to <code>bash goostats.sh</code>:</p>
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
 </div>
 <p>When she presses <kbd>Enter</kbd>, the shell runs the modified
 command. However, nothing appears to happen — there is no output. After
@@ -4538,15 +4538,15 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb40">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span><span class="kw">;</span></span>
-<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a><span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span><span class="kw">;</span></span>
+<span id="cb40-2"><a href="#cb40-2" tabindex="-1"></a><span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
 </div>
-<div id="beginning-and-end" class="callout callout">
+<div id="callout4" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="beginning-and-end" class="callout-inner">
-<h3 class="callout-title">Beginning and End<a class="anchor" aria-label="anchor" href="#beginning-and-end"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="beginning-and-end">Beginning and End<a class="anchor" aria-label="anchor" href="#beginning-and-end"></a>
 </h3>
 <div class="callout-content">
 <p>We can move to the beginning of a line in the shell by typing
@@ -4571,12 +4571,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <code>cat stats-NENE01729B.txt</code> to examine one of the output
 files. It looks good, so she decides to get some coffee and catch up on
 her reading.</p>
-<div id="those-who-know-history-can-choose-to-repeat-it" class="callout callout">
+<div id="callout5" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="those-who-know-history-can-choose-to-repeat-it" class="callout-inner">
-<h3 class="callout-title">Those Who Know History Can Choose to Repeat
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="those-who-know-history-can-choose-to-repeat-it">Those Who Know History Can Choose to Repeat
 It<a class="anchor" aria-label="anchor" href="#those-who-know-history-can-choose-to-repeat-it"></a>
 </h3>
 <div class="callout-content">
@@ -4588,7 +4588,7 @@ <h3 class="callout-title">Those Who Know History Can Choose to Repeat
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4605,12 +4605,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 </div>
 </div>
-<div id="other-history-commands" class="callout callout">
+<div id="callout6" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="other-history-commands" class="callout-inner">
-<h3 class="callout-title">Other History Commands<a class="anchor" aria-label="anchor" href="#other-history-commands"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="other-history-commands">Other History Commands<a class="anchor" aria-label="anchor" href="#other-history-commands"></a>
 </h3>
 <div class="callout-content">
 <p>There are a number of other shortcut commands for getting at the
@@ -4654,30 +4654,30 @@ <h3 class="callout-title">Doing a Dry Run<a class="anchor" aria-label="anchor" h
 <div class="codewrapper sourceCode" id="cb44">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb44-2"><a href="#cb44-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb44-3"><a href="#cb44-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     cat <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
-<span id="cb44-4"><a href="#cb44-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb44-2"><a href="#cb44-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb44-3"><a href="#cb44-3" tabindex="-1"></a><span class="op">&gt;</span>     cat <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
+<span id="cb44-4"><a href="#cb44-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>What is the difference between the two loops below, and which one
 would we want to run?</p>
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Version 1</span></span>
-<span id="cb45-2"><a href="#cb45-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb45-3"><a href="#cb45-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb45-4"><a href="#cb45-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
-<span id="cb45-5"><a href="#cb45-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="co"># Version 1</span></span>
+<span id="cb45-2"><a href="#cb45-2" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb45-3"><a href="#cb45-3" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb45-4"><a href="#cb45-4" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
+<span id="cb45-5"><a href="#cb45-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Version 2</span></span>
-<span id="cb46-2"><a href="#cb46-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb46-3"><a href="#cb46-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb46-4"><a href="#cb46-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="st">"cat </span><span class="va">$datafile</span><span class="st"> &gt;&gt; all.pdb"</span></span>
-<span id="cb46-5"><a href="#cb46-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="co"># Version 2</span></span>
+<span id="cb46-2"><a href="#cb46-2" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb46-3"><a href="#cb46-3" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb46-4"><a href="#cb46-4" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="st">"cat </span><span class="va">$datafile</span><span class="st"> &gt;&gt; all.pdb"</span></span>
+<span id="cb46-5"><a href="#cb46-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 </div>
 </div>
@@ -4687,7 +4687,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution7" aria-expanded="false" aria-controls="collapseSolution7">
   <h4 class="accordion-header" id="headingSolution7">Show me the solution</h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
 <div class="accordion-body">
 <p>The second version is the one we want to run. This prints to screen
 everything enclosed in the quote marks, expanding the loop variable name
@@ -4720,13 +4720,13 @@ <h3 class="callout-title">Nested Loops<a class="anchor" aria-label="anchor" href
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for species in cubane ethane methane</span>
-<span id="cb47-2"><a href="#cb47-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb47-3"><a href="#cb47-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     for <span class="ex">temperature</span> in 25 30 37 40</span>
-<span id="cb47-4"><a href="#cb47-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     do</span>
-<span id="cb47-5"><a href="#cb47-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>         mkdir <span class="va">$species</span><span class="ex">-</span><span class="va">$temperature</span></span>
-<span id="cb47-6"><a href="#cb47-6" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     done</span>
-<span id="cb47-7"><a href="#cb47-7" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> for species in cubane ethane methane</span>
+<span id="cb47-2"><a href="#cb47-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb47-3"><a href="#cb47-3" tabindex="-1"></a><span class="op">&gt;</span>     for <span class="ex">temperature</span> in 25 30 37 40</span>
+<span id="cb47-4"><a href="#cb47-4" tabindex="-1"></a><span class="op">&gt;</span>     do</span>
+<span id="cb47-5"><a href="#cb47-5" tabindex="-1"></a><span class="op">&gt;</span>         mkdir <span class="va">$species</span><span class="ex">-</span><span class="va">$temperature</span></span>
+<span id="cb47-6"><a href="#cb47-6" tabindex="-1"></a><span class="op">&gt;</span>     done</span>
+<span id="cb47-7"><a href="#cb47-7" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 </div>
 </div>
@@ -4736,7 +4736,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution8" aria-expanded="false" aria-controls="collapseSolution8">
   <h4 class="accordion-header" id="headingSolution8">Show me the solution</h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
 <div class="accordion-body">
 <p>We have a nested loop, i.e. contained within another loop, so for
 each species in the outer loop, the inner loop (the nested loop)
@@ -4835,8 +4835,8 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd alkanes</span>
-<span id="cb1-2"><a href="#cb1-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> cd alkanes</span>
+<span id="cb1-2"><a href="#cb1-2" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <p>The command <code>nano middle.sh</code> opens the file
 <code>middle.sh</code> within the text editor ‘nano’ (which runs within
@@ -4858,7 +4858,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4871,12 +4871,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 <p>Sure enough, our script’s output is exactly what we would get if we
 ran that pipeline directly.</p>
-<div id="text-vs.-whatever" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="text-vs.-whatever" class="callout-inner">
-<h3 class="callout-title">Text vs. Whatever<a class="anchor" aria-label="anchor" href="#text-vs.-whatever"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="text-vs--whatever">Text vs. Whatever<a class="anchor" aria-label="anchor" href="#text-vs--whatever"></a>
 </h3>
 <div class="callout-content">
 <p>We usually call programs like Microsoft Word or LibreOffice Writer
@@ -4900,7 +4900,7 @@ <h3 class="callout-title">Text vs. Whatever<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <p>Now, within “nano”, replace the text <code>octane.pdb</code> with the
 special variable called <code>$1</code>:</p>
@@ -4911,7 +4911,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh octane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh octane.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4926,7 +4926,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4937,12 +4937,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 ATOM     12  H           1      -0.048  -1.362  -0.205  1.00  0.00
 ATOM     13  H           1      -1.183   0.500  -1.412  1.00  0.00</code></pre>
 </div>
-<div id="double-quotes-around-arguments" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="double-quotes-around-arguments" class="callout-inner">
-<h3 class="callout-title">Double-Quotes Around Arguments<a class="anchor" aria-label="anchor" href="#double-quotes-around-arguments"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="double-quotes-around-arguments">Double-Quotes Around Arguments<a class="anchor" aria-label="anchor" href="#double-quotes-around-arguments"></a>
 </h3>
 <div class="callout-content">
 <p>For the same reason that we put the loop variable inside
@@ -4964,14 +4964,14 @@ <h3 class="callout-title">Double-Quotes Around Arguments<a class="anchor" aria-l
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <pre class="source"><code>head -n "$2" "$1" | tail -n "$3"</code></pre>
 <p>We can now run:</p>
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 15 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 15 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4987,7 +4987,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 20 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 20 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5005,7 +5005,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <pre class="source"><code># Select lines from the middle of a file.
 # Usage: bash middle.sh filename end_line num_lines
@@ -5022,7 +5022,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
 </div>
 <p>because <code>wc -l</code> lists the number of lines in the files
 (recall that <code>wc</code> stands for ‘word count’, adding the
@@ -5042,7 +5042,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano sorted.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> nano sorted.sh</span></code></pre>
 </div>
 <pre class="source"><code># Sort files by their length.
 # Usage: bash sorted.sh one_or_more_filenames
@@ -5050,7 +5050,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash sorted.sh <span class="pp">*</span>.pdb ../creatures/<span class="pp">*</span>.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> bash sorted.sh <span class="pp">*</span>.pdb ../creatures/<span class="pp">*</span>.dat</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5108,16 +5108,16 @@ <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script to find unique species in csv files where species is the second data field</span></span>
-<span id="cb25-2"><a href="#cb25-2" aria-hidden="true" tabindex="-1"></a><span class="co"># This script accepts any number of file names as command line arguments</span></span>
-<span id="cb25-3"><a href="#cb25-3" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb25-4"><a href="#cb25-4" aria-hidden="true" tabindex="-1"></a><span class="co"># Loop over all files</span></span>
-<span id="cb25-5"><a href="#cb25-5" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> file <span class="kw">in</span> <span class="va">$@</span></span>
-<span id="cb25-6"><a href="#cb25-6" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb25-7"><a href="#cb25-7" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="st">"Unique species in </span><span class="va">$file</span><span class="st">:"</span></span>
-<span id="cb25-8"><a href="#cb25-8" aria-hidden="true" tabindex="-1"></a>    <span class="co"># Extract species names</span></span>
-<span id="cb25-9"><a href="#cb25-9" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 2 <span class="va">$file</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span>
-<span id="cb25-10"><a href="#cb25-10" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="co"># Script to find unique species in csv files where species is the second data field</span></span>
+<span id="cb25-2"><a href="#cb25-2" tabindex="-1"></a><span class="co"># This script accepts any number of file names as command line arguments</span></span>
+<span id="cb25-3"><a href="#cb25-3" tabindex="-1"></a></span>
+<span id="cb25-4"><a href="#cb25-4" tabindex="-1"></a><span class="co"># Loop over all files</span></span>
+<span id="cb25-5"><a href="#cb25-5" tabindex="-1"></a><span class="cf">for</span> file <span class="kw">in</span> <span class="va">$@</span></span>
+<span id="cb25-6"><a href="#cb25-6" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb25-7"><a href="#cb25-7" tabindex="-1"></a>    <span class="bu">echo</span> <span class="st">"Unique species in </span><span class="va">$file</span><span class="st">:"</span></span>
+<span id="cb25-8"><a href="#cb25-8" tabindex="-1"></a>    <span class="co"># Extract species names</span></span>
+<span id="cb25-9"><a href="#cb25-9" tabindex="-1"></a>    <span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 2 <span class="va">$file</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span>
+<span id="cb25-10"><a href="#cb25-10" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 </div>
 </div>
@@ -5131,7 +5131,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> redo-figure-3.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> redo-figure-3.sh</span></code></pre>
 </div>
 <p>The file <code>redo-figure-3.sh</code> now contains:</p>
 <pre class="source"><code>297 bash goostats.sh NENE01729B.txt stats-NENE01729B.txt
@@ -5156,7 +5156,7 @@ <h3 class="callout-title">Why Record Commands in the History Before
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> recent.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> recent.sh</span></code></pre>
 </div>
 <p>the last command in the file is the <code>history</code> command
 itself, i.e., the shell has added <code>history</code> to the command
@@ -5197,37 +5197,37 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb29">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ../../north-pacific-gyre/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="ex">$</span> cd ../../north-pacific-gyre/</span></code></pre>
 </div>
 <p>She creates a file using <code>nano</code> …</p>
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano do-stats.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> nano do-stats.sh</span></code></pre>
 </div>
 <p>…which contains the following:</p>
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
-<span id="cb31-2"><a href="#cb31-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
-<span id="cb31-3"><a href="#cb31-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb31-4"><a href="#cb31-4" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
-<span id="cb31-5"><a href="#cb31-5" aria-hidden="true" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb31-6"><a href="#cb31-6" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
+<span id="cb31-2"><a href="#cb31-2" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
+<span id="cb31-3"><a href="#cb31-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb31-4"><a href="#cb31-4" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
+<span id="cb31-5"><a href="#cb31-5" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb31-6"><a href="#cb31-6" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <p>She saves this in a file called <code>do-stats.sh</code> so that she
 can now re-do the first stage of her analysis by typing:</p>
 <div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
 </div>
 <p>She can also do this:</p>
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt <span class="kw">|</span> <span class="fu">wc</span> <span class="at">-l</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt <span class="kw">|</span> <span class="fu">wc</span> <span class="at">-l</span></span></code></pre>
 </div>
 <p>so that the output is just the number of files processed rather than
 the names of the files that were processed.</p>
@@ -5237,12 +5237,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Calculate stats for Site A and Site B data files.</span></span>
-<span id="cb34-2"><a href="#cb34-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
-<span id="cb34-3"><a href="#cb34-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb34-4"><a href="#cb34-4" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
-<span id="cb34-5"><a href="#cb34-5" aria-hidden="true" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb34-6"><a href="#cb34-6" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="co"># Calculate stats for Site A and Site B data files.</span></span>
+<span id="cb34-2"><a href="#cb34-2" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
+<span id="cb34-3"><a href="#cb34-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb34-4"><a href="#cb34-4" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
+<span id="cb34-5"><a href="#cb34-5" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb34-6"><a href="#cb34-6" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <p>The advantage is that this always selects the right files: she
 doesn’t have to remember to exclude the ‘Z’ files. The disadvantage is
@@ -5267,15 +5267,15 @@ <h3 class="callout-title">Variables in Shell Scripts<a class="anchor" aria-label
 <div class="codewrapper sourceCode" id="cb35">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" aria-hidden="true" tabindex="-1"></a><span class="fu">head</span> <span class="at">-n</span> <span class="va">$2</span> <span class="va">$1</span></span>
-<span id="cb35-2"><a href="#cb35-2" aria-hidden="true" tabindex="-1"></a><span class="fu">tail</span> <span class="at">-n</span> <span class="va">$3</span> <span class="va">$1</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" tabindex="-1"></a><span class="fu">head</span> <span class="at">-n</span> <span class="va">$2</span> <span class="va">$1</span></span>
+<span id="cb35-2"><a href="#cb35-2" tabindex="-1"></a><span class="fu">tail</span> <span class="at">-n</span> <span class="va">$3</span> <span class="va">$1</span></span></code></pre>
 </div>
 <p>While you are in the <code>alkanes</code> directory, you type the
 following command:</p>
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash script.sh <span class="st">'*.pdb'</span> 1 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> bash script.sh <span class="st">'*.pdb'</span> 1 1</span></code></pre>
 </div>
 <p>Which of the following outputs would you expect to see?</p>
 <ol style="list-style-type: decimal">
@@ -5305,8 +5305,8 @@ <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span>
-<span id="cb37-2"><a href="#cb37-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span>
+<span id="cb37-2"><a href="#cb37-2" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span></code></pre>
 </div>
 <p>The shell does not expand <code>'*.pdb'</code> because it is enclosed
 by quote marks. As such, the first argument to the script is
@@ -5332,7 +5332,7 @@ <h3 class="callout-title">Find the Longest File With a Given
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/alkanes pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/alkanes pdb</span></code></pre>
 </div>
 <p>would print the name of the <code>.pdb</code> file in
 <code>shell-lesson-data/exercise-data/alkanes</code> that has the most
@@ -5341,7 +5341,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/writing txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/writing txt</span></code></pre>
 </div>
 </div>
 </div>
@@ -5356,13 +5356,13 @@ <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb40">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Shell script which takes two arguments:</span></span>
-<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a><span class="co">#    1. a directory name</span></span>
-<span id="cb40-3"><a href="#cb40-3" aria-hidden="true" tabindex="-1"></a><span class="co">#    2. a file extension</span></span>
-<span id="cb40-4"><a href="#cb40-4" aria-hidden="true" tabindex="-1"></a><span class="co"># and prints the name of the file in that directory</span></span>
-<span id="cb40-5"><a href="#cb40-5" aria-hidden="true" tabindex="-1"></a><span class="co"># with the most lines which matches the file extension.</span></span>
-<span id="cb40-6"><a href="#cb40-6" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb40-7"><a href="#cb40-7" aria-hidden="true" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$1</span>/<span class="pp">*</span>.<span class="va">$2</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 2 <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" tabindex="-1"></a><span class="co"># Shell script which takes two arguments:</span></span>
+<span id="cb40-2"><a href="#cb40-2" tabindex="-1"></a><span class="co">#    1. a directory name</span></span>
+<span id="cb40-3"><a href="#cb40-3" tabindex="-1"></a><span class="co">#    2. a file extension</span></span>
+<span id="cb40-4"><a href="#cb40-4" tabindex="-1"></a><span class="co"># and prints the name of the file in that directory</span></span>
+<span id="cb40-5"><a href="#cb40-5" tabindex="-1"></a><span class="co"># with the most lines which matches the file extension.</span></span>
+<span id="cb40-6"><a href="#cb40-6" tabindex="-1"></a></span>
+<span id="cb40-7"><a href="#cb40-7" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$1</span>/<span class="pp">*</span>.<span class="va">$2</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 2 <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
 </div>
 <p>The first part of the pipeline, <code>wc -l $1/*.$2 | sort -n</code>,
 counts the lines in each file and sorts them numerically (largest last).
@@ -5395,23 +5395,23 @@ <h3 class="callout-title">Script Reading Comprehension<a class="anchor" aria-lab
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script 1</span></span>
-<span id="cb41-2"><a href="#cb41-2" aria-hidden="true" tabindex="-1"></a><span class="bu">echo</span> <span class="pp">*</span>.<span class="pp">*</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="co"># Script 1</span></span>
+<span id="cb41-2"><a href="#cb41-2" tabindex="-1"></a><span class="bu">echo</span> <span class="pp">*</span>.<span class="pp">*</span></span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script 2</span></span>
-<span id="cb42-2"><a href="#cb42-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> filename <span class="kw">in</span> <span class="va">$1</span> <span class="va">$2</span> <span class="va">$3</span></span>
-<span id="cb42-3"><a href="#cb42-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb42-4"><a href="#cb42-4" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$filename</span></span>
-<span id="cb42-5"><a href="#cb42-5" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="co"># Script 2</span></span>
+<span id="cb42-2"><a href="#cb42-2" tabindex="-1"></a><span class="cf">for</span> filename <span class="kw">in</span> <span class="va">$1</span> <span class="va">$2</span> <span class="va">$3</span></span>
+<span id="cb42-3"><a href="#cb42-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb42-4"><a href="#cb42-4" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$filename</span></span>
+<span id="cb42-5"><a href="#cb42-5" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script 3</span></span>
-<span id="cb43-2"><a href="#cb43-2" aria-hidden="true" tabindex="-1"></a><span class="bu">echo</span> <span class="va">$@</span>.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="co"># Script 3</span></span>
+<span id="cb43-2"><a href="#cb43-2" tabindex="-1"></a><span class="bu">echo</span> <span class="va">$@</span>.pdb</span></code></pre>
 </div>
 </div>
 </div>
@@ -5459,26 +5459,26 @@ <h3 class="callout-title">Debugging Scripts<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
-<span id="cb45-2"><a href="#cb45-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
-<span id="cb45-3"><a href="#cb45-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb45-4"><a href="#cb45-4" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datfile</span></span>
-<span id="cb45-5"><a href="#cb45-5" aria-hidden="true" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb45-6"><a href="#cb45-6" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
+<span id="cb45-2"><a href="#cb45-2" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
+<span id="cb45-3"><a href="#cb45-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb45-4"><a href="#cb45-4" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datfile</span></span>
+<span id="cb45-5"><a href="#cb45-5" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb45-6"><a href="#cb45-6" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <p>When you run it from the <code>north-pacific-gyre</code>
 directory:</p>
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="ex">$</span> bash do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
 </div>
 <p>the output is blank. To figure out why, re-run the script using the
 <code>-x</code> option:</p>
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash <span class="at">-x</span> do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> bash <span class="at">-x</span> do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
 </div>
 <p>What is the output showing you? Which line is responsible for the
 error?</p>
@@ -5587,9 +5587,9 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd</span>
-<span id="cb1-2"><a href="#cb1-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data/writing</span>
-<span id="cb1-3"><a href="#cb1-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cat haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> cd</span>
+<span id="cb1-2"><a href="#cb1-2" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data/writing</span>
+<span id="cb1-3"><a href="#cb1-3" tabindex="-1"></a><span class="ex">$</span> cat haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5610,7 +5610,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep not haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> grep not haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5633,7 +5633,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep The haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> grep The haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5652,7 +5652,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> The haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> The haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5666,7 +5666,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> <span class="st">"is not"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> <span class="st">"is not"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5683,7 +5683,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="st">"it"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="st">"it"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5701,7 +5701,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5714,7 +5714,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-i</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-i</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5729,7 +5729,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-v</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-v</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5752,7 +5752,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-r</span> Yesterday .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-r</span> Yesterday .</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5767,7 +5767,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">--help</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">--help</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5829,12 +5829,12 @@ <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </div>
 </div>
 </div>
-<div id="wildcards" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="wildcards" class="callout-inner">
-<h3 class="callout-title">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="wildcards">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a>
 </h3>
 <div class="callout-content">
 <p><code>grep</code>‘s real power doesn’t come from its options, though;
@@ -5848,7 +5848,7 @@ <h3 class="callout-title">Wildcards<a class="anchor" aria-label="anchor" href="#
 <div class="codewrapper sourceCode" id="cb24">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-E</span> <span class="st">"^.o"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-E</span> <span class="st">"^.o"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5899,13 +5899,13 @@ <h3 class="callout-title">Tracking a Species<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> : <span class="at">-f</span> 2</span>
-<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span></span>
-<span id="cb28-3"><a href="#cb28-3" aria-hidden="true" tabindex="-1"></a><span class="kw">|</span></span>
-<span id="cb28-4"><a href="#cb28-4" aria-hidden="true" tabindex="-1"></a><span class="fu">grep</span> <span class="at">-w</span> <span class="va">$1</span> <span class="at">-r</span> <span class="va">$2</span></span>
-<span id="cb28-5"><a href="#cb28-5" aria-hidden="true" tabindex="-1"></a><span class="kw">|</span></span>
-<span id="cb28-6"><a href="#cb28-6" aria-hidden="true" tabindex="-1"></a><span class="va">$1</span><span class="ex">.txt</span></span>
-<span id="cb28-7"><a href="#cb28-7" aria-hidden="true" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 1,3</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> : <span class="at">-f</span> 2</span>
+<span id="cb28-2"><a href="#cb28-2" tabindex="-1"></a><span class="op">&gt;</span></span>
+<span id="cb28-3"><a href="#cb28-3" tabindex="-1"></a><span class="kw">|</span></span>
+<span id="cb28-4"><a href="#cb28-4" tabindex="-1"></a><span class="fu">grep</span> <span class="at">-w</span> <span class="va">$1</span> <span class="at">-r</span> <span class="va">$2</span></span>
+<span id="cb28-5"><a href="#cb28-5" tabindex="-1"></a><span class="kw">|</span></span>
+<span id="cb28-6"><a href="#cb28-6" tabindex="-1"></a><span class="va">$1</span><span class="ex">.txt</span></span>
+<span id="cb28-7"><a href="#cb28-7" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 1,3</span></code></pre>
 </div>
 <p>Hint: use <code>man grep</code> to look for how to grep text
 recursively in a directory and <code>man cut</code> to select more than
@@ -5931,7 +5931,7 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash count-species.sh bear .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> bash count-species.sh bear .</span></code></pre>
 </div>
 </div>
 </div>
@@ -6031,7 +6031,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> find .</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -6067,7 +6067,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> d</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> d</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -6084,7 +6084,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> f</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> f</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -6107,7 +6107,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb40">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="pp">*</span>.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="pp">*</span>.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -6122,7 +6122,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> numbers.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> numbers.txt</span></code></pre>
 </div>
 <p><code>find</code> did what we asked; we just asked for the wrong
 thing.</p>
@@ -6134,7 +6134,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="st">"*.txt"</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="st">"*.txt"</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -6143,12 +6143,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <span><span class="va">.</span><span class="op">/</span><span class="va">writing</span><span class="op">/</span><span class="va">haiku.txt</span></span>
 <span><span class="va">.</span><span class="op">/</span><span class="va">numbers.txt</span></span></code></pre>
 </div>
-<div id="listing-vs.-finding" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="listing-vs.-finding" class="callout-inner">
-<h3 class="callout-title">Listing vs. Finding<a class="anchor" aria-label="anchor" href="#listing-vs.-finding"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="listing-vs--finding">Listing vs. Finding<a class="anchor" aria-label="anchor" href="#listing-vs--finding"></a>
 </h3>
 <div class="callout-content">
 <p><code>ls</code> and <code>find</code> can be made to do similar
@@ -6168,7 +6168,7 @@ <h3 class="callout-title">Listing vs. Finding<a class="anchor" aria-label="anch
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -6188,7 +6188,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> ./writing/LittleWomen.txt ./writing/haiku.txt ./numbers.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> ./writing/LittleWomen.txt ./writing/haiku.txt ./numbers.txt</span></code></pre>
 </div>
 <p>which is what we wanted. This expansion is exactly what the shell
 does when it expands wildcards like <code>*</code> and <code>?</code>,
@@ -6202,7 +6202,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb48">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="st">"searching"</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="st">"searching"</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -6254,12 +6254,12 @@ <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 </div>
 </div>
 </div>
-<div id="binary-files" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="binary-files" class="callout-inner">
-<h3 class="callout-title">Binary Files<a class="anchor" aria-label="anchor" href="#binary-files"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="binary-files">Binary Files<a class="anchor" aria-label="anchor" href="#binary-files"></a>
 </h3>
 <div class="callout-content">
 <p>We have focused exclusively on finding patterns in text files. What
@@ -6305,7 +6305,7 @@ <h3 class="callout-title">
 <div class="codewrapper sourceCode" id="cb50">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" aria-hidden="true" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.dat"</span><span class="va">)</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.dat"</span><span class="va">)</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
 </div>
 </div>
 </div>
@@ -6401,8 +6401,8 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "url": "https://swcarpentry.github.io/shell-novice/aio.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/aio.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-02-27",
-  "datePublished": "2024-02-27"
+  "dateModified": "2024-03-05",
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/discuss.html b/discuss.html
index 7cc097a81..88a39b4ba 100644
--- a/discuss.html
+++ b/discuss.html
@@ -389,7 +389,7 @@ <h1>Discussion</h1>
   "identifier": "https://swcarpentry.github.io/shell-novice/discuss.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-05-02",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/images.html b/images.html
index 9f88396e7..80fd3edab 100644
--- a/images.html
+++ b/images.html
@@ -390,8 +390,8 @@ <h3 id="05-loop-figure-1">Figure 1</h3>
   "url": "https://swcarpentry.github.io/shell-novice/images.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/images.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-02-27",
-  "datePublished": "2024-02-27"
+  "dateModified": "2024-03-05",
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/index.html b/index.html
index 1f0e1c1b0..2aa52fefc 100644
--- a/index.html
+++ b/index.html
@@ -316,14 +316,13 @@ <h3 class="callout-title">Prerequisites<a class="anchor" aria-label="anchor" hre
 folder as your working directory.</li>
 </ol><p>In the lesson, you will find out how to access the data files in this
 folder.</p>
-<div id="where-to-type-commands-how-to-open-a-new-shell" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="where-to-type-commands-how-to-open-a-new-shell" class="callout-inner">
-<h3 class="callout-title">Where to type commands: How to open a new
-shell<a class="anchor" aria-label="anchor" href="#where-to-type-commands-how-to-open-a-new-shell"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="where-to-type-commands-how-to-open-a-new-shell">Where to type commands: How to open a new
+shell<a class="anchor" aria-label="anchor" href="#where-to-type-commands-how-to-open-a-new-shell"></a></h3>
 <div class="callout-content">
 <p>The shell is a program that enables us to send commands to the
 computer and receive output. It is also referred to as the terminal or
@@ -456,8 +455,8 @@ <h4 class="accordion-header" id="headingSolution3">Linux</h4>
   "url": "https://swcarpentry.github.io/shell-novice/index.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/index.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-02-27",
-  "datePublished": "2024-02-27"
+  "dateModified": "2024-03-05",
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor-notes.html b/instructor-notes.html
index cb7f5cb9e..c48dc63c5 100644
--- a/instructor-notes.html
+++ b/instructor-notes.html
@@ -488,7 +488,7 @@ <h1>Instructor Notes</h1>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="va">PS1</span><span class="op">=</span><span class="st">'$ '</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="va">PS1</span><span class="op">=</span><span class="st">'$ '</span></span></code></pre>
 </div>
 </li>
 <li><p>On Windows machines if <code>nano</code> hasn’t been properly
@@ -503,8 +503,8 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb2">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd</span>
-<span id="cb2-2"><a href="#cb2-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" tabindex="-1"></a><span class="ex">$</span> cd</span>
+<span id="cb2-2"><a href="#cb2-2" tabindex="-1"></a><span class="ex">$</span> cd Desktop</span></code></pre>
 </div>
 <p>will always put someone on their desktop (unless their machine is
 backed up using enterprise OneDrive, see next point). Have them create
@@ -521,8 +521,8 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd <span class="st">"~/OneDrive - Name Of Enterprise/Desktop"</span></span>
-<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd <span class="st">"C:/Users/Username/OneDrive - Name Of Enterprise/Desktop"</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> cd <span class="st">"~/OneDrive - Name Of Enterprise/Desktop"</span></span>
+<span id="cb3-2"><a href="#cb3-2" tabindex="-1"></a><span class="ex">$</span> cd <span class="st">"C:/Users/Username/OneDrive - Name Of Enterprise/Desktop"</span></span></code></pre>
 </div>
 <p>One way to spot if the computer is using this kind of configuration
 is to look at files, folders or links on the desktop. Usually the icon
@@ -623,8 +623,8 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
   "url": "https://swcarpentry.github.io/shell-novice/instructor-notes.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor-notes.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-02-27",
-  "datePublished": "2024-02-27"
+  "dateModified": "2024-03-05",
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/01-intro.html b/instructor/01-intro.html
index 255411ea9..8871c5205 100644
--- a/instructor/01-intro.html
+++ b/instructor/01-intro.html
@@ -364,7 +364,7 @@ <h3 id="the-shell">The Shell<a class="anchor" aria-label="anchor" href="#the-she
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span></span></code></pre>
 </div>
 <p>The shell typically uses <code>$</code> as the prompt, but may use a
 different symbol. In the examples for this lesson, we’ll show the prompt
@@ -384,7 +384,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb2">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="ex">nelle@localhost</span> $</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" tabindex="-1"></a><span class="ex">nelle@localhost</span> $</span></code></pre>
 </div>
 <p>The prompt might even include more than this. Do not worry if your
 prompt is not just a short <code>$</code>. This lesson does not depend
@@ -397,7 +397,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -405,20 +405,19 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <pre class="output" tabindex="0"><code>Desktop     Downloads   Movies      Pictures
 Documents   Library     Music       Public</code></pre>
 </div>
-<div id="command-not-found" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="command-not-found" class="callout-inner">
-<h3 class="callout-title">Command not found<a class="anchor" aria-label="anchor" href="#command-not-found"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="command-not-found">Command not found<a class="anchor" aria-label="anchor" href="#command-not-found"></a></h3>
 <div class="callout-content">
 <p>If the shell can’t find a program whose name is the command you
 typed, it will print an error message such as:</p>
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ks</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> ks</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -544,7 +543,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/01-intro.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-06-09",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/02-filedir.html b/instructor/02-filedir.html
index 8d2b4b575..567d9053b 100644
--- a/instructor/02-filedir.html
+++ b/instructor/02-filedir.html
@@ -320,7 +320,7 @@ <h3 class="card-title">Objectives</h3>
   <h3 class="accordion-header" id="headingInstructor1">
 <div class="note-square"><i aria-hidden="true" class="callout-icon" data-feather="edit-2"></i></div>Instructor Note</h3>
 </button>
-<div id="collapseInstructor1" class="accordion-collapse collapse" data-bs-parent="#accordionInstructor1" aria-labelledby="headingInstructor1">
+<div id="collapseInstructor1" class="accordion-collapse collapse" aria-labelledby="headingInstructor1" data-bs-parent="#accordionInstructor1">
 <div class="accordion-body">
 <p>Introducing and navigating the filesystem in the shell (covered in <a href="02-filedir.html">Navigating Files and Directories</a> section) can
 be confusing. You may have both terminal and GUI file explorer open side
@@ -348,7 +348,7 @@ <h3 class="accordion-header" id="headingInstructor1">
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -357,13 +357,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 <p>Here, the computer’s response is <code>/Users/nelle</code>, which is
 Nelle’s <strong>home directory</strong>:</p>
-<div id="home-directory-variation" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="home-directory-variation" class="callout-inner">
-<h3 class="callout-title">Home Directory Variation<a class="anchor" aria-label="anchor" href="#home-directory-variation"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="home-directory-variation">Home Directory Variation<a class="anchor" aria-label="anchor" href="#home-directory-variation"></a></h3>
 <div class="callout-content">
 <p>The home directory path will look different on different operating
 systems. On Linux, it may look like <code>/home/nelle</code>, and on
@@ -402,13 +401,12 @@ <h3 class="callout-title">Home Directory Variation<a class="anchor" aria-label="
 first part of its name. Similarly, we know that <code>/Users</code> is
 stored inside the root directory <code>/</code> because its name begins
 with <code>/</code>.</p>
-<div id="slashes" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="slashes" class="callout-inner">
-<h3 class="callout-title">Slashes<a class="anchor" aria-label="anchor" href="#slashes"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="slashes">Slashes<a class="anchor" aria-label="anchor" href="#slashes"></a></h3>
 <div class="callout-content">
 <p>Notice that there are two meanings for the <code>/</code> character.
 When it appears at the front of a file or directory name, it refers to
@@ -433,7 +431,7 @@ <h3 class="callout-title">Slashes<a class="anchor" aria-label="anchor" href="#sl
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -458,7 +456,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -470,13 +468,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <strong>sub-directories</strong>. Any names in the output that don’t
 have a classification symbol are <strong>files</strong> in the current
 working directory.</p>
-<div id="clearing-your-terminal" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="clearing-your-terminal" class="callout-inner">
-<h3 class="callout-title">Clearing your terminal<a class="anchor" aria-label="anchor" href="#clearing-your-terminal"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="clearing-your-terminal">Clearing your terminal<a class="anchor" aria-label="anchor" href="#clearing-your-terminal"></a></h3>
 <div class="callout-content">
 <p>If your screen gets too cluttered, you can clear your terminal using
 the <code>clear</code> command. You can still access previous commands
@@ -496,23 +493,22 @@ <h3 id="getting-help">Getting help<a class="anchor" aria-label="anchor" href="#g
 </ol><div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
 </div>
 <ol start="2" style="list-style-type: decimal"><li>We can read its manual with <code>man</code> (available on Linux and
 macOS):</li>
 </ol><div class="codewrapper sourceCode" id="cb8">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
 </div>
 <p>We’ll describe both ways next.</p>
-<div id="help-for-built-in-commands" class="callout callout">
+<div id="callout4" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="help-for-built-in-commands" class="callout-inner">
-<h3 class="callout-title">Help for built-in commands<a class="anchor" aria-label="anchor" href="#help-for-built-in-commands"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="help-for-built-in-commands">Help for built-in commands<a class="anchor" aria-label="anchor" href="#help-for-built-in-commands"></a></h3>
 <div class="callout-content">
 <p>Some commands are built in to the Bash shell, rather than existing as
 separate programs on the filesystem. One example is the <code>cd</code>
@@ -531,7 +527,7 @@ <h4 id="the---help-option">The <code>--help</code> option<a class="anchor" aria-
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -562,20 +558,19 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
   -F, --classify             append indicator (one of */=&gt;@|) to entries
 ...        ...        ...</code></pre>
 </div>
-<div id="unsupported-command-line-options" class="callout callout">
+<div id="callout5" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="unsupported-command-line-options" class="callout-inner">
-<h3 class="callout-title">Unsupported command-line options<a class="anchor" aria-label="anchor" href="#unsupported-command-line-options"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="unsupported-command-line-options">Unsupported command-line options<a class="anchor" aria-label="anchor" href="#unsupported-command-line-options"></a></h3>
 <div class="callout-content">
 <p>If you try to use an option that is not supported, <code>ls</code>
 and other commands will usually print an error message similar to:</p>
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-j</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-j</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -593,7 +588,7 @@ <h4 id="the-man-command">The <code>man</code> command<a class="anchor" aria-labe
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
 </div>
 <p>This command will turn your terminal into a page with a description
 of the <code>ls</code> command and its options.</p>
@@ -607,13 +602,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <kbd>Shift</kbd>+<kbd>N</kbd> (for moving backward).</p>
 <p>To <strong>quit</strong> the <code>man</code> pages, press
 <kbd>Q</kbd>.</p>
-<div id="manual-pages-on-the-web" class="callout callout">
+<div id="callout6" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="manual-pages-on-the-web" class="callout-inner">
-<h3 class="callout-title">Manual pages on the web<a class="anchor" aria-label="anchor" href="#manual-pages-on-the-web"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="manual-pages-on-the-web">Manual pages on the web<a class="anchor" aria-label="anchor" href="#manual-pages-on-the-web"></a></h3>
 <div class="callout-content">
 <p>Of course, there is a third way to access help for commands:
 searching the internet via your web browser. When using internet search,
@@ -648,7 +642,7 @@ <h3 class="callout-title">Exploring More<code>ls</code>Options<a class="anchor"
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>The <code>-l</code> option makes <code>ls</code> use a
 <strong>l</strong>ong listing format, showing not only the
@@ -684,7 +678,7 @@ <h3 class="callout-title">Listing in Reverse Chronological Order<a class="anchor
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>The most recently changed file is listed last when using
 <code>-rt</code>. This can be very useful for finding your most recent
@@ -708,7 +702,7 @@ <h3 id="exploring-other-directories">Exploring Other Directories<a class="anchor
 <div class="codewrapper sourceCode" id="cb14">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb14-1"><a href="#cb14-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb14-1"><a href="#cb14-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -739,7 +733,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb16">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop/shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop/shell-lesson-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -761,9 +755,9 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop</span>
-<span id="cb18-2"><a href="#cb18-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span>
-<span id="cb18-3"><a href="#cb18-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> cd Desktop</span>
+<span id="cb18-2"><a href="#cb18-2" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span>
+<span id="cb18-3"><a href="#cb18-3" tabindex="-1"></a><span class="ex">$</span> cd exercise-data</span></code></pre>
 </div>
 <p>These commands will move us from our home directory into our Desktop
 directory, then into the <code>shell-lesson-data</code> directory, then
@@ -780,7 +774,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -790,7 +784,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -803,7 +797,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb23">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -820,7 +814,7 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ..</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="ex">$</span> cd ..</span></code></pre>
 </div>
 <p><code>..</code> is a special directory name meaning “the directory
 containing this one”, or more succinctly, the <strong>parent</strong> of
@@ -830,7 +824,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -843,7 +837,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> <span class="at">-a</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> <span class="at">-a</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -861,13 +855,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <p>Note that in most command line tools, multiple options can be
 combined with a single <code>-</code> and no spaces between the options;
 <code>ls -F -a</code> is equivalent to <code>ls -Fa</code>.</p>
-<div id="other-hidden-files" class="callout callout">
+<div id="callout7" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="other-hidden-files" class="callout-inner">
-<h3 class="callout-title">Other Hidden Files<a class="anchor" aria-label="anchor" href="#other-hidden-files"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="other-hidden-files">Other Hidden Files<a class="anchor" aria-label="anchor" href="#other-hidden-files"></a></h3>
 <div class="callout-content">
 <p>In addition to the hidden directories <code>..</code> and
 <code>.</code>, you may also see a file called
@@ -889,14 +882,14 @@ <h3 class="callout-title">Other Hidden Files<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> cd</span></code></pre>
 </div>
 <p>How can you check what happened? <code>pwd</code> gives us the
 answer!</p>
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -913,7 +906,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data</span></code></pre>
 </div>
 <p>Check that we’ve moved to the right place by running <code>pwd</code>
 and <code>ls -F</code>.</p>
@@ -939,7 +932,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -949,17 +942,16 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd /Users/nelle/Desktop/shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> cd /Users/nelle/Desktop/shell-lesson-data</span></code></pre>
 </div>
 <p>Run <code>pwd</code> and <code>ls -F</code> to ensure that we’re in
 the directory we expect.</p>
-<div id="two-more-shortcuts" class="callout callout">
+<div id="callout8" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="two-more-shortcuts" class="callout-inner">
-<h3 class="callout-title">Two More Shortcuts<a class="anchor" aria-label="anchor" href="#two-more-shortcuts"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="two-more-shortcuts">Two More Shortcuts<a class="anchor" aria-label="anchor" href="#two-more-shortcuts"></a></h3>
 <div class="callout-content">
 <p>The shell interprets a tilde (<code>~</code>) character at the start
 of a path to mean “the current user’s home directory”. For example, if
@@ -982,20 +974,20 @@ <h3 class="callout-title">Two More Shortcuts<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span></code></pre>
 </div>
 <p>Then <code>cd</code> into the <code>exercise-data/creatures</code>
 directory</p>
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/creatures</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/creatures</span></code></pre>
 </div>
 <p>Now if you run</p>
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd <span class="at">-</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> cd <span class="at">-</span></span></code></pre>
 </div>
 <p>you’ll see you’re back in <code>~/Desktop/shell-lesson-data</code>.
 Run <code>cd -</code> again and you’re back in
@@ -1031,7 +1023,7 @@ <h3 class="callout-title">Absolute vs Relative Paths<a class="anchor" aria-label
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>No: <code>.</code> stands for the current directory.</li>
 <li>No: <code>/</code> stands for the root directory.</li>
@@ -1072,7 +1064,7 @@ <h3 class="callout-title">Relative Path Resolution<a class="anchor" aria-label="
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>No: there <em>is</em> a directory <code>backup</code> in
 <code>/Users</code>.</li>
@@ -1114,7 +1106,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5">Show me the solution</h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>No: <code>pwd</code> is not the name of a directory.</li>
 <li>Yes: <code>ls</code> without directory argument lists files and
@@ -1134,7 +1126,7 @@ <h4 class="accordion-header" id="headingSolution5">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
 </div>
 <figure><img src="../fig/shell_command_syntax.svg" alt="General syntax of a shell command" class="figure mx-auto d-block"></figure><p><code>ls</code> is the <strong>command</strong>, with an
 <strong>option</strong> <code>-F</code> and an <strong>argument</strong>
@@ -1160,8 +1152,8 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span>
-<span id="cb42-2"><a href="#cb42-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-s</span> exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span>
+<span id="cb42-2"><a href="#cb42-2" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-s</span> exercise-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1176,7 +1168,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb44">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-S</span> exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-S</span> exercise-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1190,7 +1182,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1199,13 +1191,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 Library/              Users/
 Network/              Volumes/</code></pre>
 </div>
-<div id="when-to-use-short-or-long-options" class="callout callout">
+<div id="callout9" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="when-to-use-short-or-long-options" class="callout-inner">
-<h3 class="callout-title">When to use short or long options<a class="anchor" aria-label="anchor" href="#when-to-use-short-or-long-options"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="when-to-use-short-or-long-options">When to use short or long options<a class="anchor" aria-label="anchor" href="#when-to-use-short-or-long-options"></a></h3>
 <div class="callout-content">
 <p>When options exist as both short and long options:</p>
 <ul><li>Use the short option when typing commands directly into the shell to
@@ -1235,7 +1226,7 @@ <h3 id="nelles-pipeline-organizing-files">Nelle’s Pipeline: Organizing Files<a
 <div class="codewrapper sourceCode" id="cb48">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
 </div>
 <p>This command is a lot to type, but she can let the shell do most of
 the work through what is called <strong>tab completion</strong>. If she
@@ -1243,14 +1234,14 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb49">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls nor</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" tabindex="-1"></a><span class="ex">$</span> ls nor</span></code></pre>
 </div>
 <p>and then presses <kbd>Tab</kbd> (the tab key on her keyboard), the
 shell automatically completes the directory name for her:</p>
 <div class="codewrapper sourceCode" id="cb50">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
 </div>
 <p>Pressing <kbd>Tab</kbd> again does nothing, since there are multiple
 possibilities; pressing <kbd>Tab</kbd> twice brings up a list of all the
@@ -1261,15 +1252,15 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb51">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb51-1"><a href="#cb51-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/goo</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb51-1"><a href="#cb51-1" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/goo</span></code></pre>
 </div>
 <p>To see all of those files, she can press <kbd>Tab</kbd> twice
 more.</p>
 <div class="codewrapper sourceCode" id="cb52">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" aria-hidden="true" tabindex="-1"></a><span class="fu">ls</span> north-pacific-gyre/goo</span>
-<span id="cb52-2"><a href="#cb52-2" aria-hidden="true" tabindex="-1"></a><span class="ex">goodiff.sh</span>   goostats.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" tabindex="-1"></a><span class="fu">ls</span> north-pacific-gyre/goo</span>
+<span id="cb52-2"><a href="#cb52-2" tabindex="-1"></a><span class="ex">goodiff.sh</span>   goostats.sh</span></code></pre>
 </div>
 <p>This is called <strong>tab completion</strong>, and we will see it in
 many other tools as we go on.</p>
@@ -1372,7 +1363,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/02-filedir.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2024-01-08",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/03-create.html b/instructor/03-create.html
index 2f0f2e1e3..dbe3542b5 100644
--- a/instructor/03-create.html
+++ b/instructor/03-create.html
@@ -325,7 +325,7 @@ <h3 id="step-one-see-where-we-are-and-what-we-already-have">Step one: see where
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -337,8 +337,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/writing/</span>
-<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/writing/</span>
+<span id="cb3-2"><a href="#cb3-2" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -353,7 +353,7 @@ <h3 id="create-a-directory">Create a directory<a class="anchor" aria-label="anch
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> mkdir thesis</span></code></pre>
 </div>
 <p>As you might guess from its name, <code>mkdir</code> means ‘make
 directory’. Since <code>thesis</code> is a relative path (i.e., does not
@@ -362,7 +362,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb6">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -374,7 +374,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb8">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> thesis</span></code></pre>
 </div>
 <p>Note that <code>mkdir</code> is not limited to creating single
 directories one at a time. The <code>-p</code> option allows
@@ -383,7 +383,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> ../project/data ../project/results</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> ../project/data ../project/results</span></code></pre>
 </div>
 <p>The <code>-R</code> option to the <code>ls</code> command will list
 all nested subdirectories within a directory. Let’s use
@@ -392,7 +392,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-FR</span> ../project</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-FR</span> ../project</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -404,13 +404,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 
 ../project/results:</code></pre>
 </div>
-<div id="two-ways-of-doing-the-same-thing" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="two-ways-of-doing-the-same-thing" class="callout-inner">
-<h3 class="callout-title">Two ways of doing the same thing<a class="anchor" aria-label="anchor" href="#two-ways-of-doing-the-same-thing"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="two-ways-of-doing-the-same-thing">Two ways of doing the same thing<a class="anchor" aria-label="anchor" href="#two-ways-of-doing-the-same-thing"></a></h3>
 <div class="callout-content">
 <p>Using the shell to create a directory is no different than using a
 file explorer. If you open the current directory using your operating
@@ -421,13 +420,12 @@ <h3 class="callout-title">Two ways of doing the same thing<a class="anchor" aria
 </div>
 </div>
 </div>
-<div id="good-names-for-files-and-directories" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="good-names-for-files-and-directories" class="callout-inner">
-<h3 class="callout-title">Good names for files and directories<a class="anchor" aria-label="anchor" href="#good-names-for-files-and-directories"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="good-names-for-files-and-directories">Good names for files and directories<a class="anchor" aria-label="anchor" href="#good-names-for-files-and-directories"></a></h3>
 <div class="callout-content">
 <p>Complicated names of files and directories can make your life painful
 when working on the command line. Here we provide a few useful tips for
@@ -481,16 +479,15 @@ <h3 id="create-a-text-file">Create a text file<a class="anchor" aria-label="anch
 <div class="codewrapper sourceCode" id="cb12">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd thesis</span>
-<span id="cb12-2"><a href="#cb12-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano draft.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" tabindex="-1"></a><span class="ex">$</span> cd thesis</span>
+<span id="cb12-2"><a href="#cb12-2" tabindex="-1"></a><span class="ex">$</span> nano draft.txt</span></code></pre>
 </div>
-<div id="which-editor" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="which-editor" class="callout-inner">
-<h3 class="callout-title">Which Editor?<a class="anchor" aria-label="anchor" href="#which-editor"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="which-editor">Which Editor?<a class="anchor" aria-label="anchor" href="#which-editor"></a></h3>
 <div class="callout-content">
 <p>When we say, ‘<code>nano</code> is a text editor’ we really do mean
 ‘text’. It can only work with plain character data, not tables, images,
@@ -522,13 +519,12 @@ <h3 class="callout-title">Which Editor?<a class="anchor" aria-label="anchor" hre
 to accept the suggested default of <code>draft.txt</code>.</p>
 <p>Once our file is saved, we can use <kbd>Ctrl</kbd>+<kbd>X</kbd> to
 quit the editor and return to the shell.</p>
-<div id="control-ctrl-or-key" class="callout callout">
+<div id="callout4" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="control-ctrl-or-key" class="callout-inner">
-<h3 class="callout-title">Control, Ctrl, or ^ Key<a class="anchor" aria-label="anchor" href="#control-ctrl-or-key"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="control-ctrl-or-key">Control, Ctrl, or ^ Key<a class="anchor" aria-label="anchor" href="#control-ctrl-or-key"></a></h3>
 <div class="callout-content">
 <p>The Control key is also called the ‘Ctrl’ key. There are various ways
 in which using the Control key may be described. For example, you may
@@ -553,7 +549,7 @@ <h3 class="callout-title">Control, Ctrl, or ^ Key<a class="anchor" aria-label="a
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -573,7 +569,7 @@ <h3 class="callout-title">Creating Files a Different Way<a class="anchor" aria-l
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> touch my_file.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> touch my_file.txt</span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li><p>What did the <code>touch</code> command do? When you look at your
 current directory using the GUI file explorer, does the file show
@@ -624,18 +620,17 @@ <h3 class="callout-title">Creating Files a Different Way<em>(continued)</em><a c
 <div class="codewrapper sourceCode" id="cb16">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm my_file.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" tabindex="-1"></a><span class="ex">$</span> rm my_file.txt</span></code></pre>
 </div>
 </div>
 </div>
 </div>
-<div id="whats-in-a-name" class="callout callout">
+<div id="callout5" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="whats-in-a-name" class="callout-inner">
-<h3 class="callout-title">What’s In A Name?<a class="anchor" aria-label="anchor" href="#whats-in-a-name"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="whats-in-a-name">What’s In A Name?<a class="anchor" aria-label="anchor" href="#whats-in-a-name"></a></h3>
 <div class="callout-content">
 <p>You may have noticed that all of Nelle’s files are named ‘something
 dot something’, and in this part of the lesson, we always used the
@@ -670,7 +665,7 @@ <h3 class="callout-title">What’s In A Name?<a class="anchor" aria-label="ancho
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data/exercise-data/writing</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data/exercise-data/writing</span></code></pre>
 </div>
 <p>In our <code>thesis</code> directory we have a file
 <code>draft.txt</code> which isn’t a particularly informative name, so
@@ -679,7 +674,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv thesis/draft.txt thesis/quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> mv thesis/draft.txt thesis/quotes.txt</span></code></pre>
 </div>
 <p>The first argument tells <code>mv</code> what we’re ‘moving’, while
 the second is where it’s to go. In this case, we’re moving
@@ -690,7 +685,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -715,7 +710,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv thesis/quotes.txt .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">$</span> mv thesis/quotes.txt .</span></code></pre>
 </div>
 <p>The effect is to move the file from the directory it was in to the
 current working directory. <code>ls</code> now shows us that
@@ -723,7 +718,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -736,7 +731,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb24">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis/quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> ls thesis/quotes.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -751,7 +746,7 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -773,18 +768,18 @@ <h3 class="callout-title">Moving Files to a new folder<a class="anchor" aria-lab
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span>
-<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">analyzed/</span> raw/</span>
-<span id="cb28-3"><a href="#cb28-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> analyzed</span>
-<span id="cb28-4"><a href="#cb28-4" aria-hidden="true" tabindex="-1"></a><span class="ex">fructose.dat</span> glucose.dat maltose.dat sucrose.dat</span>
-<span id="cb28-5"><a href="#cb28-5" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd analyzed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span>
+<span id="cb28-2"><a href="#cb28-2" tabindex="-1"></a> <span class="ex">analyzed/</span> raw/</span>
+<span id="cb28-3"><a href="#cb28-3" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> analyzed</span>
+<span id="cb28-4"><a href="#cb28-4" tabindex="-1"></a><span class="ex">fructose.dat</span> glucose.dat maltose.dat sucrose.dat</span>
+<span id="cb28-5"><a href="#cb28-5" tabindex="-1"></a><span class="ex">$</span> cd analyzed</span></code></pre>
 </div>
 <p>Fill in the blanks to move these files to the <code>raw/</code>
 folder (i.e. the one she forgot to put them in)</p>
 <div class="codewrapper sourceCode" id="cb29">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ____/____</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ____/____</span></code></pre>
 </div>
 </div>
 </div>
@@ -799,7 +794,7 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ../raw</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ../raw</span></code></pre>
 </div>
 <p>Recall that <code>..</code> refers to the parent directory (i.e. one
 above the current directory) and that <code>.</code> refers to the
@@ -818,8 +813,8 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp quotes.txt thesis/quotations.txt</span>
-<span id="cb31-2"><a href="#cb31-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt thesis/quotations.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="ex">$</span> cp quotes.txt thesis/quotations.txt</span>
+<span id="cb31-2"><a href="#cb31-2" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt thesis/quotations.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -831,14 +826,14 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="at">-r</span> thesis thesis_backup</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="at">-r</span> thesis thesis_backup</span></code></pre>
 </div>
 <p>We can check the result by listing the contents of both the
 <code>thesis</code> and <code>thesis_backup</code> directory:</p>
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis thesis_backup</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> ls thesis thesis_backup</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -856,8 +851,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp thesis thesis_backup</span>
-<span id="cb36-2"><a href="#cb36-2" aria-hidden="true" tabindex="-1"></a><span class="ex">cp:</span> <span class="at">-r</span> not specified<span class="kw">;</span> <span class="ex">omitting</span> directory <span class="st">'thesis'</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> cp thesis thesis_backup</span>
+<span id="cb36-2"><a href="#cb36-2" tabindex="-1"></a><span class="ex">cp:</span> <span class="at">-r</span> not specified<span class="kw">;</span> <span class="ex">omitting</span> directory <span class="st">'thesis'</span></span></code></pre>
 </div>
 <div id="renaming-files" class="callout challenge">
 <div class="callout-square">
@@ -912,7 +907,7 @@ <h3 class="callout-title">Moving and Copying<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -922,7 +917,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -932,10 +927,10 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir recombined</span>
-<span id="cb41-2"><a href="#cb41-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv proteins.dat recombined/</span>
-<span id="cb41-3"><a href="#cb41-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp recombined/proteins.dat ../proteins-saved.dat</span>
-<span id="cb41-4"><a href="#cb41-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="ex">$</span> mkdir recombined</span>
+<span id="cb41-2"><a href="#cb41-2" tabindex="-1"></a><span class="ex">$</span> mv proteins.dat recombined/</span>
+<span id="cb41-3"><a href="#cb41-3" tabindex="-1"></a><span class="ex">$</span> cp recombined/proteins.dat ../proteins-saved.dat</span>
+<span id="cb41-4"><a href="#cb41-4" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li><code>proteins-saved.dat recombined</code></li>
 <li><code>recombined</code></li>
@@ -985,26 +980,25 @@ <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> rm quotes.txt</span></code></pre>
 </div>
 <p>We can confirm the file has gone using <code>ls</code>:</p>
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="error" tabindex="0"><code>ls: cannot access 'quotes.txt': No such file or directory</code></pre>
 </div>
-<div id="deleting-is-forever" class="callout callout">
+<div id="callout6" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="deleting-is-forever" class="callout-inner">
-<h3 class="callout-title">Deleting Is Forever<a class="anchor" aria-label="anchor" href="#deleting-is-forever"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="deleting-is-forever">Deleting Is Forever<a class="anchor" aria-label="anchor" href="#deleting-is-forever"></a></h3>
 <div class="callout-content">
 <p>The Unix shell doesn’t have a trash bin that we can recover deleted
 files from (though most graphical interfaces to Unix do). Instead, when
@@ -1057,7 +1051,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="ex">$</span> rm thesis</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1072,7 +1066,7 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb48">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm <span class="at">-r</span> thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" tabindex="-1"></a><span class="ex">$</span> rm <span class="at">-r</span> thesis</span></code></pre>
 </div>
 <p>Given that there is no way to retrieve files deleted using the shell,
 <code>rm -r</code> <em>should be used with great caution</em> (you might
@@ -1099,16 +1093,16 @@ <h3 class="callout-title">Copy with Multiple Filenames<a class="anchor" aria-lab
 <div class="codewrapper sourceCode" id="cb49">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir backup</span>
-<span id="cb49-2"><a href="#cb49-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp creatures/minotaur.dat creatures/unicorn.dat backup/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" tabindex="-1"></a><span class="ex">$</span> mkdir backup</span>
+<span id="cb49-2"><a href="#cb49-2" tabindex="-1"></a><span class="ex">$</span> cp creatures/minotaur.dat creatures/unicorn.dat backup/</span></code></pre>
 </div>
 <p>In the example below, what does <code>cp</code> do when given three
 or more file names?</p>
 <div class="codewrapper sourceCode" id="cb50">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd creatures</span>
-<span id="cb50-2"><a href="#cb50-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" tabindex="-1"></a><span class="ex">$</span> cd creatures</span>
+<span id="cb50-2"><a href="#cb50-2" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1118,7 +1112,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb52">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp minotaur.dat unicorn.dat basilisk.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" tabindex="-1"></a><span class="ex">$</span> cp minotaur.dat unicorn.dat basilisk.dat</span></code></pre>
 </div>
 </div>
 </div>
@@ -1147,13 +1141,12 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 </div>
 <div class="section level3">
 <h3 id="using-wildcards-for-accessing-multiple-files-at-once">Using wildcards for accessing multiple files at once<a class="anchor" aria-label="anchor" href="#using-wildcards-for-accessing-multiple-files-at-once"></a></h3>
-<div id="wildcards" class="callout callout">
+<div id="callout7" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="wildcards" class="callout-inner">
-<h3 class="callout-title">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="wildcards">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a></h3>
 <div class="callout-content">
 <p><code>*</code> is a <strong>wildcard</strong>, which represents zero
 or more other characters. Let’s consider the
@@ -1244,25 +1237,25 @@ <h3 class="callout-title">More on Wildcards<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb54">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb54-1"><a href="#cb54-1" aria-hidden="true" tabindex="-1"></a><span class="bu">.</span></span>
-<span id="cb54-2"><a href="#cb54-2" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
-<span id="cb54-3"><a href="#cb54-3" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
-<span id="cb54-4"><a href="#cb54-4" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
-<span id="cb54-5"><a href="#cb54-5" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
-<span id="cb54-6"><a href="#cb54-6" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
-<span id="cb54-7"><a href="#cb54-7" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
-<span id="cb54-8"><a href="#cb54-8" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
-<span id="cb54-9"><a href="#cb54-9" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
-<span id="cb54-10"><a href="#cb54-10" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
-<span id="cb54-11"><a href="#cb54-11" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
-<span id="cb54-12"><a href="#cb54-12" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
-<span id="cb54-13"><a href="#cb54-13" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
-<span id="cb54-14"><a href="#cb54-14" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> backup</span>
-<span id="cb54-15"><a href="#cb54-15" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
-<span id="cb54-16"><a href="#cb54-16" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
-<span id="cb54-17"><a href="#cb54-17" aria-hidden="true" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
-<span id="cb54-18"><a href="#cb54-18" aria-hidden="true" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
-<span id="cb54-19"><a href="#cb54-19" aria-hidden="true" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb54-1"><a href="#cb54-1" tabindex="-1"></a><span class="bu">.</span></span>
+<span id="cb54-2"><a href="#cb54-2" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
+<span id="cb54-3"><a href="#cb54-3" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
+<span id="cb54-4"><a href="#cb54-4" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
+<span id="cb54-5"><a href="#cb54-5" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
+<span id="cb54-6"><a href="#cb54-6" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
+<span id="cb54-7"><a href="#cb54-7" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
+<span id="cb54-8"><a href="#cb54-8" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
+<span id="cb54-9"><a href="#cb54-9" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
+<span id="cb54-10"><a href="#cb54-10" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
+<span id="cb54-11"><a href="#cb54-11" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
+<span id="cb54-12"><a href="#cb54-12" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
+<span id="cb54-13"><a href="#cb54-13" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
+<span id="cb54-14"><a href="#cb54-14" tabindex="-1"></a><span class="ex">├──</span> backup</span>
+<span id="cb54-15"><a href="#cb54-15" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
+<span id="cb54-16"><a href="#cb54-16" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
+<span id="cb54-17"><a href="#cb54-17" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
+<span id="cb54-18"><a href="#cb54-18" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
+<span id="cb54-19"><a href="#cb54-19" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span></code></pre>
 </div>
 <p>Before heading off to another field trip, she wants to back up her
 data and send some datasets to her colleague Bob. Sam uses the following
@@ -1270,57 +1263,57 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb55">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb55-1"><a href="#cb55-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>dataset<span class="pp">*</span> backup/datasets</span>
-<span id="cb55-2"><a href="#cb55-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp ____calibration____ backup/calibration</span>
-<span id="cb55-3"><a href="#cb55-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp 2015-____-____ send_to_bob/all_november_files/</span>
-<span id="cb55-4"><a href="#cb55-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp ____ send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb55-1"><a href="#cb55-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>dataset<span class="pp">*</span> backup/datasets</span>
+<span id="cb55-2"><a href="#cb55-2" tabindex="-1"></a><span class="ex">$</span> cp ____calibration____ backup/calibration</span>
+<span id="cb55-3"><a href="#cb55-3" tabindex="-1"></a><span class="ex">$</span> cp 2015-____-____ send_to_bob/all_november_files/</span>
+<span id="cb55-4"><a href="#cb55-4" tabindex="-1"></a><span class="ex">$</span> cp ____ send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
 </div>
 <p>Help Sam by filling in the blanks.</p>
 <p>The resulting directory structure should look like this</p>
 <div class="codewrapper sourceCode" id="cb56">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb56-1"><a href="#cb56-1" aria-hidden="true" tabindex="-1"></a><span class="bu">.</span></span>
-<span id="cb56-2"><a href="#cb56-2" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
-<span id="cb56-3"><a href="#cb56-3" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
-<span id="cb56-4"><a href="#cb56-4" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
-<span id="cb56-5"><a href="#cb56-5" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
-<span id="cb56-6"><a href="#cb56-6" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
-<span id="cb56-7"><a href="#cb56-7" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
-<span id="cb56-8"><a href="#cb56-8" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
-<span id="cb56-9"><a href="#cb56-9" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
-<span id="cb56-10"><a href="#cb56-10" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
-<span id="cb56-11"><a href="#cb56-11" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
-<span id="cb56-12"><a href="#cb56-12" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
-<span id="cb56-13"><a href="#cb56-13" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
-<span id="cb56-14"><a href="#cb56-14" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> backup</span>
-<span id="cb56-15"><a href="#cb56-15" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
-<span id="cb56-16"><a href="#cb56-16" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-23-calibration.txt</span>
-<span id="cb56-17"><a href="#cb56-17" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-26-calibration.txt</span>
-<span id="cb56-18"><a href="#cb56-18" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> │   └── 2015-11-23-calibration.txt</span>
-<span id="cb56-19"><a href="#cb56-19" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
-<span id="cb56-20"><a href="#cb56-20" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset1.txt</span>
-<span id="cb56-21"><a href="#cb56-21" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset2.txt</span>
-<span id="cb56-22"><a href="#cb56-22" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset_overview.txt</span>
-<span id="cb56-23"><a href="#cb56-23" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset1.txt</span>
-<span id="cb56-24"><a href="#cb56-24" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset2.txt</span>
-<span id="cb56-25"><a href="#cb56-25" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset_overview.txt</span>
-<span id="cb56-26"><a href="#cb56-26" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset1.txt</span>
-<span id="cb56-27"><a href="#cb56-27" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset2.txt</span>
-<span id="cb56-28"><a href="#cb56-28" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     └── 2015-11-23-dataset_overview.txt</span>
-<span id="cb56-29"><a href="#cb56-29" aria-hidden="true" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
-<span id="cb56-30"><a href="#cb56-30" aria-hidden="true" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
-<span id="cb56-31"><a href="#cb56-31" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset1.txt</span>
-<span id="cb56-32"><a href="#cb56-32" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset2.txt</span>
-<span id="cb56-33"><a href="#cb56-33" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset_overview.txt</span>
-<span id="cb56-34"><a href="#cb56-34" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset1.txt</span>
-<span id="cb56-35"><a href="#cb56-35" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset2.txt</span>
-<span id="cb56-36"><a href="#cb56-36" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> └── 2015-11-23-dataset_overview.txt</span>
-<span id="cb56-37"><a href="#cb56-37" aria-hidden="true" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span>
-<span id="cb56-38"><a href="#cb56-38" aria-hidden="true" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-calibration.txt</span>
-<span id="cb56-39"><a href="#cb56-39" aria-hidden="true" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
-<span id="cb56-40"><a href="#cb56-40" aria-hidden="true" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
-<span id="cb56-41"><a href="#cb56-41" aria-hidden="true" tabindex="-1"></a>        <span class="ex">└──</span> 2015-11-23-dataset_overview.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb56-1"><a href="#cb56-1" tabindex="-1"></a><span class="bu">.</span></span>
+<span id="cb56-2"><a href="#cb56-2" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
+<span id="cb56-3"><a href="#cb56-3" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
+<span id="cb56-4"><a href="#cb56-4" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
+<span id="cb56-5"><a href="#cb56-5" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
+<span id="cb56-6"><a href="#cb56-6" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
+<span id="cb56-7"><a href="#cb56-7" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
+<span id="cb56-8"><a href="#cb56-8" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
+<span id="cb56-9"><a href="#cb56-9" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
+<span id="cb56-10"><a href="#cb56-10" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
+<span id="cb56-11"><a href="#cb56-11" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
+<span id="cb56-12"><a href="#cb56-12" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
+<span id="cb56-13"><a href="#cb56-13" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
+<span id="cb56-14"><a href="#cb56-14" tabindex="-1"></a><span class="ex">├──</span> backup</span>
+<span id="cb56-15"><a href="#cb56-15" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
+<span id="cb56-16"><a href="#cb56-16" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-23-calibration.txt</span>
+<span id="cb56-17"><a href="#cb56-17" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-26-calibration.txt</span>
+<span id="cb56-18"><a href="#cb56-18" tabindex="-1"></a><span class="ex">│  </span> │   └── 2015-11-23-calibration.txt</span>
+<span id="cb56-19"><a href="#cb56-19" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
+<span id="cb56-20"><a href="#cb56-20" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset1.txt</span>
+<span id="cb56-21"><a href="#cb56-21" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset2.txt</span>
+<span id="cb56-22"><a href="#cb56-22" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset_overview.txt</span>
+<span id="cb56-23"><a href="#cb56-23" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset1.txt</span>
+<span id="cb56-24"><a href="#cb56-24" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset2.txt</span>
+<span id="cb56-25"><a href="#cb56-25" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset_overview.txt</span>
+<span id="cb56-26"><a href="#cb56-26" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset1.txt</span>
+<span id="cb56-27"><a href="#cb56-27" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset2.txt</span>
+<span id="cb56-28"><a href="#cb56-28" tabindex="-1"></a><span class="ex">│  </span>     └── 2015-11-23-dataset_overview.txt</span>
+<span id="cb56-29"><a href="#cb56-29" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
+<span id="cb56-30"><a href="#cb56-30" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
+<span id="cb56-31"><a href="#cb56-31" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset1.txt</span>
+<span id="cb56-32"><a href="#cb56-32" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset2.txt</span>
+<span id="cb56-33"><a href="#cb56-33" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset_overview.txt</span>
+<span id="cb56-34"><a href="#cb56-34" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset1.txt</span>
+<span id="cb56-35"><a href="#cb56-35" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset2.txt</span>
+<span id="cb56-36"><a href="#cb56-36" tabindex="-1"></a>    <span class="ex">│  </span> └── 2015-11-23-dataset_overview.txt</span>
+<span id="cb56-37"><a href="#cb56-37" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span>
+<span id="cb56-38"><a href="#cb56-38" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-calibration.txt</span>
+<span id="cb56-39"><a href="#cb56-39" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
+<span id="cb56-40"><a href="#cb56-40" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
+<span id="cb56-41"><a href="#cb56-41" tabindex="-1"></a>        <span class="ex">└──</span> 2015-11-23-dataset_overview.txt</span></code></pre>
 </div>
 </div>
 </div>
@@ -1335,9 +1328,9 @@ <h4 class="accordion-header" id="headingSolution8">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb57">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb57-1"><a href="#cb57-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>calibration.txt backup/calibration</span>
-<span id="cb57-2"><a href="#cb57-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp 2015-11-<span class="pp">*</span> send_to_bob/all_november_files/</span>
-<span id="cb57-3"><a href="#cb57-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>-23-dataset<span class="pp">*</span> send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb57-1"><a href="#cb57-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>calibration.txt backup/calibration</span>
+<span id="cb57-2"><a href="#cb57-2" tabindex="-1"></a><span class="ex">$</span> cp 2015-11-<span class="pp">*</span> send_to_bob/all_november_files/</span>
+<span id="cb57-3"><a href="#cb57-3" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>-23-dataset<span class="pp">*</span> send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
 </div>
 </div>
 </div>
@@ -1356,7 +1349,7 @@ <h3 class="callout-title">Organizing Directories and Files<a class="anchor" aria
 <div class="codewrapper sourceCode" id="cb58">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb58-1"><a href="#cb58-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb58-1"><a href="#cb58-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1370,7 +1363,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb60">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb60-1"><a href="#cb60-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb60-1"><a href="#cb60-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1380,7 +1373,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb62">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb62-1"><a href="#cb62-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls analyzed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb62-1"><a href="#cb62-1" tabindex="-1"></a><span class="ex">$</span> ls analyzed</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1400,7 +1393,7 @@ <h4 class="accordion-header" id="headingSolution9">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb64">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb64-1"><a href="#cb64-1" aria-hidden="true" tabindex="-1"></a><span class="fu">mv</span> <span class="pp">*</span>.dat analyzed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb64-1"><a href="#cb64-1" tabindex="-1"></a><span class="fu">mv</span> <span class="pp">*</span>.dat analyzed</span></code></pre>
 </div>
 <p>Jamie needs to move her files <code>fructose.dat</code> and
 <code>sucrose.dat</code> to the <code>analyzed</code> directory. The
@@ -1442,39 +1435,39 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb66">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb66-1"><a href="#cb66-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
-<span id="cb66-2"><a href="#cb66-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data</span>
-<span id="cb66-3"><a href="#cb66-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span>
-<span id="cb66-4"><a href="#cb66-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb66-1"><a href="#cb66-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
+<span id="cb66-2"><a href="#cb66-2" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data</span>
+<span id="cb66-3"><a href="#cb66-3" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span>
+<span id="cb66-4"><a href="#cb66-4" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb67">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb67-1"><a href="#cb67-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
-<span id="cb67-2"><a href="#cb67-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
-<span id="cb67-3"><a href="#cb67-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
-<span id="cb67-4"><a href="#cb67-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd data</span>
-<span id="cb67-5"><a href="#cb67-5" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb67-1"><a href="#cb67-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
+<span id="cb67-2"><a href="#cb67-2" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
+<span id="cb67-3"><a href="#cb67-3" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
+<span id="cb67-4"><a href="#cb67-4" tabindex="-1"></a><span class="ex">$</span> cd data</span>
+<span id="cb67-5"><a href="#cb67-5" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb68">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb68-1"><a href="#cb68-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span>
-<span id="cb68-2"><a href="#cb68-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb68-1"><a href="#cb68-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span>
+<span id="cb68-2"><a href="#cb68-2" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb69">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb69-1"><a href="#cb69-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/raw</span>
-<span id="cb69-2"><a href="#cb69-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb69-1"><a href="#cb69-1" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/raw</span>
+<span id="cb69-2"><a href="#cb69-2" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/processed</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb70">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb70-1"><a href="#cb70-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
-<span id="cb70-2"><a href="#cb70-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
-<span id="cb70-3"><a href="#cb70-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
-<span id="cb70-4"><a href="#cb70-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb70-1"><a href="#cb70-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
+<span id="cb70-2"><a href="#cb70-2" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
+<span id="cb70-3"><a href="#cb70-3" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
+<span id="cb70-4"><a href="#cb70-4" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
 </div>
 </div>
 </div>
@@ -1599,7 +1592,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/03-create.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-07-31",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/04-pipefilter.html b/instructor/04-pipefilter.html
index 777d5a859..b496e2c49 100644
--- a/instructor/04-pipefilter.html
+++ b/instructor/04-pipefilter.html
@@ -324,7 +324,7 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -336,7 +336,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc cubane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> wc cubane.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -353,7 +353,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="pp">*</span>.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="pp">*</span>.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -373,7 +373,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -389,20 +389,19 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <p>The <code>-m</code> and <code>-w</code> options can also be used with
 the <code>wc</code> command to show only the number of characters or the
 number of words, respectively.</p>
-<div id="why-isnt-it-doing-anything" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="why-isnt-it-doing-anything" class="callout-inner">
-<h3 class="callout-title">Why Isn’t It Doing Anything?<a class="anchor" aria-label="anchor" href="#why-isnt-it-doing-anything"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="why-isnt-it-doing-anything">Why Isn’t It Doing Anything?<a class="anchor" aria-label="anchor" href="#why-isnt-it-doing-anything"></a></h3>
 <div class="callout-content">
 <p>What happens if a command is supposed to process a file, but we don’t
 give it a filename? For example, what if we type:</p>
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span></span></code></pre>
 </div>
 <p>but don’t type <code>*.pdb</code> (or anything else) after the
 command? Since it doesn’t have any filenames, <code>wc</code> assumes it
@@ -425,7 +424,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="op">&gt;</span> lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="op">&gt;</span> lengths.txt</span></code></pre>
 </div>
 <p>The greater than symbol, <code>&gt;</code>, tells the shell to
 <strong>redirect</strong> the command’s output to a file instead of
@@ -439,7 +438,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> ls lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -454,7 +453,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cat lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> cat lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -467,13 +466,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
   15  propane.pdb
  107  total</code></pre>
 </div>
-<div id="output-page-by-page" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="output-page-by-page" class="callout-inner">
-<h3 class="callout-title">Output Page by Page<a class="anchor" aria-label="anchor" href="#output-page-by-page"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="output-page-by-page">Output Page by Page<a class="anchor" aria-label="anchor" href="#output-page-by-page"></a></h3>
 <div class="callout-content">
 <p>We’ll continue to use <code>cat</code> in this lesson, for
 convenience and consistency, but it has the disadvantage that it always
@@ -549,7 +547,7 @@ <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -572,8 +570,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> sorted-lengths.txt</span>
-<span id="cb20-2"><a href="#cb20-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 sorted-lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> sorted-lengths.txt</span>
+<span id="cb20-2"><a href="#cb20-2" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 sorted-lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -585,20 +583,19 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 20, and so on. Since <code>sorted-lengths.txt</code> contains the
 lengths of our files ordered from least to greatest, the output of
 <code>head</code> must be the file with the fewest lines.</p>
-<div id="redirecting-to-the-same-file" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="redirecting-to-the-same-file" class="callout-inner">
-<h3 class="callout-title">Redirecting to the same file<a class="anchor" aria-label="anchor" href="#redirecting-to-the-same-file"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="redirecting-to-the-same-file">Redirecting to the same file<a class="anchor" aria-label="anchor" href="#redirecting-to-the-same-file"></a></h3>
 <div class="callout-content">
 <p>It’s a very bad idea to try redirecting the output of a command that
 operates on a file to the same file. For example:</p>
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> lengths.txt</span></code></pre>
 </div>
 <p>Doing something like this may give you incorrect results and/or
 delete the contents of <code>lengths.txt</code>.</p>
@@ -621,7 +618,7 @@ <h3 class="callout-title">What Does<code>&gt;&gt;</code>Mean?<a class="anchor" a
 <div class="codewrapper sourceCode" id="cb23">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo The echo command prints text</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" tabindex="-1"></a><span class="ex">$</span> echo The echo command prints text</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -633,13 +630,13 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;</span> testfile01.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;</span> testfile01.txt</span></code></pre>
 </div>
 <p>and:</p>
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;&gt;</span> testfile02.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;&gt;</span> testfile02.txt</span></code></pre>
 </div>
 <p>Hint: Try executing each command twice in a row and then examining
 the output files.</p>
@@ -682,8 +679,8 @@ <h3 class="callout-title">Appending Data<a class="anchor" aria-label="anchor" hr
 <div class="codewrapper sourceCode" id="cb27">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 3 animals.csv <span class="op">&gt;</span> animals-subset.csv</span>
-<span id="cb27-2"><a href="#cb27-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 2 animals.csv <span class="op">&gt;&gt;</span> animals-subset.csv</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 3 animals.csv <span class="op">&gt;</span> animals-subset.csv</span>
+<span id="cb27-2"><a href="#cb27-2" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 2 animals.csv <span class="op">&gt;&gt;</span> animals-subset.csv</span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li>The first three lines of <code>animals.csv</code>
 </li>
@@ -727,7 +724,7 @@ <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -751,7 +748,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -769,7 +766,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -857,7 +854,7 @@ <h3 class="callout-title">Pipe Reading Comprehension<a class="anchor" aria-label
 <div class="codewrapper sourceCode" id="cb35">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cat animals.csv <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5 <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 3 <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-r</span> <span class="op">&gt;</span> final.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" tabindex="-1"></a><span class="ex">$</span> cat animals.csv <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5 <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 3 <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-r</span> <span class="op">&gt;</span> final.txt</span></code></pre>
 </div>
 <p>Hint: build the pipeline up one command at a time to test your
 understanding</p>
@@ -899,7 +896,7 @@ <h3 class="callout-title">Pipe Construction<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv</span></code></pre>
 </div>
 <p>The <code>cut</code> command is used to remove or ‘cut out’ certain
 sections of each line in the file, and <code>cut</code> expects the
@@ -938,7 +935,7 @@ <h4 class="accordion-header" id="headingSolution6">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span></code></pre>
 </div>
 </div>
 </div>
@@ -1002,8 +999,8 @@ <h4 class="accordion-header" id="headingSolution7">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd north-pacific-gyre</span>
-<span id="cb41-2"><a href="#cb41-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="ex">$</span> cd north-pacific-gyre</span>
+<span id="cb41-2"><a href="#cb41-2" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt</span></code></pre>
 </div>
 <p>The output is 18 lines that look like this:</p>
 <div class="codewrapper">
@@ -1021,7 +1018,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1040,7 +1037,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1058,7 +1055,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="pp">*</span>Z.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="pp">*</span>Z.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1205,7 +1202,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/04-pipefilter.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2024-01-17",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/05-loop.html b/instructor/05-loop.html
index 87b511151..050860a9f 100644
--- a/instructor/05-loop.html
+++ b/instructor/05-loop.html
@@ -329,7 +329,7 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 5 basilisk.dat minotaur.dat unicorn.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 5 basilisk.dat minotaur.dat unicorn.dat</span></code></pre>
 </div>
 <p>We would like to print out the classification for each species, which
 is given on the second line of each file. For each file, we would need
@@ -340,24 +340,24 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb2">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="co"># The word "for" indicates the start of a "For-loop" command</span></span>
-<span id="cb2-2"><a href="#cb2-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> thing <span class="kw">in</span> list_of_things </span>
-<span id="cb2-3"><a href="#cb2-3" aria-hidden="true" tabindex="-1"></a><span class="co">#The word "do" indicates the start of job execution list</span></span>
-<span id="cb2-4"><a href="#cb2-4" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span> </span>
-<span id="cb2-5"><a href="#cb2-5" aria-hidden="true" tabindex="-1"></a>    <span class="co"># Indentation within the loop is not required, but aids legibility</span></span>
-<span id="cb2-6"><a href="#cb2-6" aria-hidden="true" tabindex="-1"></a>    <span class="ex">operation_using/command</span> <span class="va">$thing</span> </span>
-<span id="cb2-7"><a href="#cb2-7" aria-hidden="true" tabindex="-1"></a><span class="co"># The word "done" indicates the end of a loop</span></span>
-<span id="cb2-8"><a href="#cb2-8" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span>  </span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" tabindex="-1"></a><span class="co"># The word "for" indicates the start of a "For-loop" command</span></span>
+<span id="cb2-2"><a href="#cb2-2" tabindex="-1"></a><span class="cf">for</span> thing <span class="kw">in</span> list_of_things </span>
+<span id="cb2-3"><a href="#cb2-3" tabindex="-1"></a><span class="co">#The word "do" indicates the start of job execution list</span></span>
+<span id="cb2-4"><a href="#cb2-4" tabindex="-1"></a><span class="cf">do</span> </span>
+<span id="cb2-5"><a href="#cb2-5" tabindex="-1"></a>    <span class="co"># Indentation within the loop is not required, but aids legibility</span></span>
+<span id="cb2-6"><a href="#cb2-6" tabindex="-1"></a>    <span class="ex">operation_using/command</span> <span class="va">$thing</span> </span>
+<span id="cb2-7"><a href="#cb2-7" tabindex="-1"></a><span class="co"># The word "done" indicates the end of a loop</span></span>
+<span id="cb2-8"><a href="#cb2-8" tabindex="-1"></a><span class="cf">done</span>  </span></code></pre>
 </div>
 <p>and we can apply this to our example like this:</p>
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in basilisk.dat minotaur.dat unicorn.dat</span>
-<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb3-3"><a href="#cb3-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
-<span id="cb3-4"><a href="#cb3-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
-<span id="cb3-5"><a href="#cb3-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> for filename in basilisk.dat minotaur.dat unicorn.dat</span>
+<span id="cb3-2"><a href="#cb3-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb3-3"><a href="#cb3-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
+<span id="cb3-4"><a href="#cb3-4" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
+<span id="cb3-5"><a href="#cb3-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -369,13 +369,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 unicorn.dat
 CLASSIFICATION: equus monoceros</code></pre>
 </div>
-<div id="follow-the-prompt" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="follow-the-prompt" class="callout-inner">
-<h3 class="callout-title">Follow the Prompt<a class="anchor" aria-label="anchor" href="#follow-the-prompt"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="follow-the-prompt">Follow the Prompt<a class="anchor" aria-label="anchor" href="#follow-the-prompt"></a></h3>
 <div class="callout-content">
 <p>The shell prompt changes from <code>$</code> to <code>&gt;</code> and
 back again as we were typing in our loop. The second prompt,
@@ -415,13 +414,12 @@ <h3 class="callout-title">Follow the Prompt<a class="anchor" aria-label="anchor"
 runs the <code>head</code> command on that file, and <code>tail</code>
 on the output of that. Since the list was only three items, the shell
 exits the <code>for</code> loop.</p>
-<div id="same-symbols-different-meanings" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="same-symbols-different-meanings" class="callout-inner">
-<h3 class="callout-title">Same Symbols, Different Meanings<a class="anchor" aria-label="anchor" href="#same-symbols-different-meanings"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="same-symbols-different-meanings">Same Symbols, Different Meanings<a class="anchor" aria-label="anchor" href="#same-symbols-different-meanings"></a></h3>
 <div class="callout-content">
 <p>Here we see <code>&gt;</code> being used as a shell prompt, whereas
 <code>&gt;</code> is also used to redirect output. Similarly,
@@ -446,19 +444,19 @@ <h3 class="callout-title">Same Symbols, Different Meanings<a class="anchor" aria
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for x in basilisk.dat minotaur.dat unicorn.dat</span>
-<span id="cb5-2"><a href="#cb5-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb5-3"><a href="#cb5-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$x</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
-<span id="cb5-4"><a href="#cb5-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> for x in basilisk.dat minotaur.dat unicorn.dat</span>
+<span id="cb5-2"><a href="#cb5-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb5-3"><a href="#cb5-3" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$x</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
+<span id="cb5-4"><a href="#cb5-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>or:</p>
 <div class="codewrapper sourceCode" id="cb6">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for temperature in basilisk.dat minotaur.dat unicorn.dat</span>
-<span id="cb6-2"><a href="#cb6-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb6-3"><a href="#cb6-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$temperature</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
-<span id="cb6-4"><a href="#cb6-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" tabindex="-1"></a><span class="ex">$</span> for temperature in basilisk.dat minotaur.dat unicorn.dat</span>
+<span id="cb6-2"><a href="#cb6-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb6-3"><a href="#cb6-3" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$temperature</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
+<span id="cb6-4"><a href="#cb6-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>it would work exactly the same way. <em>Don’t do this.</em> Programs
 are only useful if people can understand them, so meaningless names
@@ -489,15 +487,15 @@ <h3 class="callout-title">Write your own loop<a class="anchor" aria-label="ancho
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for loop_variable in 0 1 2 3 4 5 6 7 8 9</span>
-<span id="cb7-2"><a href="#cb7-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb7-3"><a href="#cb7-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$loop_variable</span></span>
-<span id="cb7-4"><a href="#cb7-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> for loop_variable in 0 1 2 3 4 5 6 7 8 9</span>
+<span id="cb7-2"><a href="#cb7-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb7-3"><a href="#cb7-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$loop_variable</span></span>
+<span id="cb7-4"><a href="#cb7-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -537,19 +535,19 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb10-2"><a href="#cb10-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb10-3"><a href="#cb10-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">*.pdb</span></span>
-<span id="cb10-4"><a href="#cb10-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb10-2"><a href="#cb10-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb10-3"><a href="#cb10-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">*.pdb</span></span>
+<span id="cb10-4"><a href="#cb10-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>Now, what is the output of the following code?</p>
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb11-2"><a href="#cb11-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb11-3"><a href="#cb11-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$datafile</span></span>
-<span id="cb11-4"><a href="#cb11-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb11-2"><a href="#cb11-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb11-3"><a href="#cb11-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$datafile</span></span>
+<span id="cb11-4"><a href="#cb11-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>Why do these two loops give different outputs?</p>
 </div>
@@ -560,7 +558,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>The first code block gives the same output on each iteration through
 the loop. Bash expands the wildcard <code>*.pdb</code> within the loop
@@ -570,10 +568,10 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb12">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in cubane.pdb  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
-<span id="cb12-2"><a href="#cb12-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb12-3"><a href="#cb12-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">cubane.pdb</span>  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
-<span id="cb12-4"><a href="#cb12-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" tabindex="-1"></a><span class="ex">$</span> for datafile in cubane.pdb  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
+<span id="cb12-2"><a href="#cb12-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb12-3"><a href="#cb12-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">cubane.pdb</span>  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
+<span id="cb12-4"><a href="#cb12-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -615,10 +613,10 @@ <h3 class="callout-title">Limiting Sets of Files<a class="anchor" aria-label="an
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in c<span class="pp">*</span></span>
-<span id="cb15-2"><a href="#cb15-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb15-3"><a href="#cb15-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
-<span id="cb15-4"><a href="#cb15-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> for filename in c<span class="pp">*</span></span>
+<span id="cb15-2"><a href="#cb15-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb15-3"><a href="#cb15-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
+<span id="cb15-4"><a href="#cb15-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li>No files are listed.</li>
 <li>All files are listed.</li>
@@ -633,7 +631,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so any file name starting with the letter c, followed by
@@ -654,10 +652,10 @@ <h3 class="callout-title">Limiting Sets of Files<em>(continued)</em><a class="an
 <div class="codewrapper sourceCode" id="cb16">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>c<span class="pp">*</span></span>
-<span id="cb16-2"><a href="#cb16-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb16-3"><a href="#cb16-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
-<span id="cb16-4"><a href="#cb16-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>c<span class="pp">*</span></span>
+<span id="cb16-2"><a href="#cb16-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb16-3"><a href="#cb16-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
+<span id="cb16-4"><a href="#cb16-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li>The same files would be listed.</li>
 <li>All the files are listed this time.</li>
@@ -673,7 +671,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so a file name with zero or more characters before a letter
@@ -695,11 +693,11 @@ <h3 class="callout-title">Saving to a File in a Loop - Part One<a class="anchor"
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> alkanes <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
-<span id="cb17-2"><a href="#cb17-2" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb17-3"><a href="#cb17-3" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$alkanes</span></span>
-<span id="cb17-4"><a href="#cb17-4" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$alkanes</span> <span class="op">&gt;</span> alkanes.pdb</span>
-<span id="cb17-5"><a href="#cb17-5" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="cf">for</span> alkanes <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
+<span id="cb17-2"><a href="#cb17-2" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb17-3"><a href="#cb17-3" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$alkanes</span></span>
+<span id="cb17-4"><a href="#cb17-4" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$alkanes</span> <span class="op">&gt;</span> alkanes.pdb</span>
+<span id="cb17-5"><a href="#cb17-5" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li>Prints <code>cubane.pdb</code>, <code>ethane.pdb</code>,
 <code>methane.pdb</code>, <code>octane.pdb</code>,
@@ -722,7 +720,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5">Show me the solution</h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>The text from each file in turn gets written to the
 <code>alkanes.pdb</code> file. However, the file gets overwritten on
@@ -745,10 +743,10 @@ <h3 class="callout-title">Saving to a File in a Loop - Part Two<a class="anchor"
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
-<span id="cb18-2"><a href="#cb18-2" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb18-3"><a href="#cb18-3" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
-<span id="cb18-4"><a href="#cb18-4" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
+<span id="cb18-2"><a href="#cb18-2" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb18-3"><a href="#cb18-3" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
+<span id="cb18-4"><a href="#cb18-4" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <ol style="list-style-type: decimal"><li>All of the text from <code>cubane.pdb</code>,
 <code>ethane.pdb</code>, <code>methane.pdb</code>,
@@ -774,7 +772,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution6" aria-expanded="false" aria-controls="collapseSolution6">
   <h4 class="accordion-header" id="headingSolution6">Show me the solution</h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <p>3 is the correct answer. <code>&gt;&gt;</code> appends to a file,
 rather than overwriting it with the redirected output from a command.
@@ -790,11 +788,11 @@ <h4 class="accordion-header" id="headingSolution6">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
-<span id="cb19-2"><a href="#cb19-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb19-3"><a href="#cb19-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
-<span id="cb19-4"><a href="#cb19-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
-<span id="cb19-5"><a href="#cb19-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
+<span id="cb19-2"><a href="#cb19-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb19-3"><a href="#cb19-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
+<span id="cb19-4"><a href="#cb19-4" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
+<span id="cb19-5"><a href="#cb19-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>The shell starts by expanding <code>*.dat</code> to create the list
 of files it will process. The <strong>loop body</strong> then executes
@@ -804,7 +802,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo hello there</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> echo hello there</span></code></pre>
 </div>
 <p>prints:</p>
 <div class="codewrapper">
@@ -818,11 +816,11 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
-<span id="cb22-2"><a href="#cb22-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb22-3"><a href="#cb22-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     <span class="va">$filename</span></span>
-<span id="cb22-4"><a href="#cb22-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
-<span id="cb22-5"><a href="#cb22-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
+<span id="cb22-2"><a href="#cb22-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb22-3"><a href="#cb22-3" tabindex="-1"></a><span class="op">&gt;</span>     <span class="va">$filename</span></span>
+<span id="cb22-4"><a href="#cb22-4" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
+<span id="cb22-5"><a href="#cb22-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>because then the first time through the loop, when
 <code>$filename</code> expanded to <code>basilisk.dat</code>, the shell
@@ -830,13 +828,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <code>head</code> and <code>tail</code> combination selects lines 81-100
 from whatever file is being processed (assuming the file has at least
 100 lines).</p>
-<div id="spaces-in-names" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="spaces-in-names" class="callout-inner">
-<h3 class="callout-title">Spaces in Names<a class="anchor" aria-label="anchor" href="#spaces-in-names"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="spaces-in-names">Spaces in Names<a class="anchor" aria-label="anchor" href="#spaces-in-names"></a></h3>
 <div class="callout-content">
 <p>Spaces are used to separate the elements of the list that we are
 going to loop over. If one of those elements contains a space character,
@@ -849,10 +846,10 @@ <h3 class="callout-title">Spaces in Names<a class="anchor" aria-label="anchor" h
 <div class="codewrapper sourceCode" id="cb24">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="st">"red dragon.dat"</span> <span class="st">"purple unicorn.dat"</span></span>
-<span id="cb24-2"><a href="#cb24-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb24-3"><a href="#cb24-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="st">"</span><span class="va">$filename</span><span class="st">"</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
-<span id="cb24-4"><a href="#cb24-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="st">"red dragon.dat"</span> <span class="st">"purple unicorn.dat"</span></span>
+<span id="cb24-2"><a href="#cb24-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb24-3"><a href="#cb24-3" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="st">"</span><span class="va">$filename</span><span class="st">"</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
+<span id="cb24-4"><a href="#cb24-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>It is simpler to avoid using spaces (or other special characters) in
 filenames.</p>
@@ -892,13 +889,13 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb27">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>.dat original-<span class="pp">*</span>.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>.dat original-<span class="pp">*</span>.dat</span></code></pre>
 </div>
 <p>because that would expand to:</p>
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp basilisk.dat minotaur.dat unicorn.dat original-<span class="pp">*</span>.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> cp basilisk.dat minotaur.dat unicorn.dat original-<span class="pp">*</span>.dat</span></code></pre>
 </div>
 <p>This wouldn’t back up our files, instead we get an error:</p>
 <div class="codewrapper">
@@ -915,10 +912,10 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
-<span id="cb30-2"><a href="#cb30-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb30-3"><a href="#cb30-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     cp <span class="va">$filename</span> original-<span class="va">$filename</span></span>
-<span id="cb30-4"><a href="#cb30-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
+<span id="cb30-2"><a href="#cb30-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb30-3"><a href="#cb30-3" tabindex="-1"></a><span class="op">&gt;</span>     cp <span class="va">$filename</span> original-<span class="va">$filename</span></span>
+<span id="cb30-4"><a href="#cb30-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>This loop runs the <code>cp</code> command once for each filename.
 The first time, when <code>$filename</code> expands to
@@ -926,19 +923,19 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cp</span> basilisk.dat original-basilisk.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="fu">cp</span> basilisk.dat original-basilisk.dat</span></code></pre>
 </div>
 <p>The second time, the command is:</p>
 <div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cp</span> minotaur.dat original-minotaur.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="fu">cp</span> minotaur.dat original-minotaur.dat</span></code></pre>
 </div>
 <p>The third and last time, the command is:</p>
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cp</span> unicorn.dat original-unicorn.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="fu">cp</span> unicorn.dat original-unicorn.dat</span></code></pre>
 </div>
 <p>Since the <code>cp</code> command does not normally produce any
 output, it’s hard to check that the loop is working correctly. However,
@@ -965,12 +962,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd</span>
-<span id="cb34-2"><a href="#cb34-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/north-pacific-gyre</span>
-<span id="cb34-3"><a href="#cb34-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
-<span id="cb34-4"><a href="#cb34-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb34-5"><a href="#cb34-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span></span>
-<span id="cb34-6"><a href="#cb34-6" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> cd</span>
+<span id="cb34-2"><a href="#cb34-2" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/north-pacific-gyre</span>
+<span id="cb34-3"><a href="#cb34-3" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
+<span id="cb34-4"><a href="#cb34-4" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb34-5"><a href="#cb34-5" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span></span>
+<span id="cb34-6"><a href="#cb34-6" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -989,10 +986,10 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
-<span id="cb36-2"><a href="#cb36-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb36-3"><a href="#cb36-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb36-4"><a href="#cb36-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
+<span id="cb36-2"><a href="#cb36-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb36-3"><a href="#cb36-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb36-4"><a href="#cb36-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1015,14 +1012,14 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
 </div>
 <p>Using the <kbd>←</kbd>, Nelle navigates to the <code>echo</code>
 command and changes it to <code>bash goostats.sh</code>:</p>
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
 </div>
 <p>When she presses <kbd>Enter</kbd>, the shell runs the modified
 command. However, nothing appears to happen — there is no output. After
@@ -1034,16 +1031,15 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb40">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span><span class="kw">;</span></span>
-<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a><span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span><span class="kw">;</span></span>
+<span id="cb40-2"><a href="#cb40-2" tabindex="-1"></a><span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
 </div>
-<div id="beginning-and-end" class="callout callout">
+<div id="callout4" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="beginning-and-end" class="callout-inner">
-<h3 class="callout-title">Beginning and End<a class="anchor" aria-label="anchor" href="#beginning-and-end"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="beginning-and-end">Beginning and End<a class="anchor" aria-label="anchor" href="#beginning-and-end"></a></h3>
 <div class="callout-content">
 <p>We can move to the beginning of a line in the shell by typing
 <kbd>Ctrl</kbd>+<kbd>A</kbd> and to the end using
@@ -1067,14 +1063,13 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <code>cat stats-NENE01729B.txt</code> to examine one of the output
 files. It looks good, so she decides to get some coffee and catch up on
 her reading.</p>
-<div id="those-who-know-history-can-choose-to-repeat-it" class="callout callout">
+<div id="callout5" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="those-who-know-history-can-choose-to-repeat-it" class="callout-inner">
-<h3 class="callout-title">Those Who Know History Can Choose to Repeat
-It<a class="anchor" aria-label="anchor" href="#those-who-know-history-can-choose-to-repeat-it"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="those-who-know-history-can-choose-to-repeat-it">Those Who Know History Can Choose to Repeat
+It<a class="anchor" aria-label="anchor" href="#those-who-know-history-can-choose-to-repeat-it"></a></h3>
 <div class="callout-content">
 <p>Another way to repeat previous work is to use the
 <code>history</code> command to get a list of the last few hundred
@@ -1084,7 +1079,7 @@ <h3 class="callout-title">Those Who Know History Can Choose to Repeat
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1101,13 +1096,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 </div>
 </div>
-<div id="other-history-commands" class="callout callout">
+<div id="callout6" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="other-history-commands" class="callout-inner">
-<h3 class="callout-title">Other History Commands<a class="anchor" aria-label="anchor" href="#other-history-commands"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="other-history-commands">Other History Commands<a class="anchor" aria-label="anchor" href="#other-history-commands"></a></h3>
 <div class="callout-content">
 <p>There are a number of other shortcut commands for getting at the
 history.</p>
@@ -1148,30 +1142,30 @@ <h3 class="callout-title">Doing a Dry Run<a class="anchor" aria-label="anchor" h
 <div class="codewrapper sourceCode" id="cb44">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb44-2"><a href="#cb44-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb44-3"><a href="#cb44-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     cat <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
-<span id="cb44-4"><a href="#cb44-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb44-2"><a href="#cb44-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb44-3"><a href="#cb44-3" tabindex="-1"></a><span class="op">&gt;</span>     cat <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
+<span id="cb44-4"><a href="#cb44-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>What is the difference between the two loops below, and which one
 would we want to run?</p>
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Version 1</span></span>
-<span id="cb45-2"><a href="#cb45-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb45-3"><a href="#cb45-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb45-4"><a href="#cb45-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
-<span id="cb45-5"><a href="#cb45-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="co"># Version 1</span></span>
+<span id="cb45-2"><a href="#cb45-2" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb45-3"><a href="#cb45-3" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb45-4"><a href="#cb45-4" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
+<span id="cb45-5"><a href="#cb45-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Version 2</span></span>
-<span id="cb46-2"><a href="#cb46-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb46-3"><a href="#cb46-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb46-4"><a href="#cb46-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="st">"cat </span><span class="va">$datafile</span><span class="st"> &gt;&gt; all.pdb"</span></span>
-<span id="cb46-5"><a href="#cb46-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="co"># Version 2</span></span>
+<span id="cb46-2"><a href="#cb46-2" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb46-3"><a href="#cb46-3" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb46-4"><a href="#cb46-4" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="st">"cat </span><span class="va">$datafile</span><span class="st"> &gt;&gt; all.pdb"</span></span>
+<span id="cb46-5"><a href="#cb46-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 </div>
 </div>
@@ -1181,7 +1175,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution7" aria-expanded="false" aria-controls="collapseSolution7">
   <h4 class="accordion-header" id="headingSolution7">Show me the solution</h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
 <div class="accordion-body">
 <p>The second version is the one we want to run. This prints to screen
 everything enclosed in the quote marks, expanding the loop variable name
@@ -1214,13 +1208,13 @@ <h3 class="callout-title">Nested Loops<a class="anchor" aria-label="anchor" href
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for species in cubane ethane methane</span>
-<span id="cb47-2"><a href="#cb47-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb47-3"><a href="#cb47-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     for <span class="ex">temperature</span> in 25 30 37 40</span>
-<span id="cb47-4"><a href="#cb47-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     do</span>
-<span id="cb47-5"><a href="#cb47-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>         mkdir <span class="va">$species</span><span class="ex">-</span><span class="va">$temperature</span></span>
-<span id="cb47-6"><a href="#cb47-6" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     done</span>
-<span id="cb47-7"><a href="#cb47-7" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> for species in cubane ethane methane</span>
+<span id="cb47-2"><a href="#cb47-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb47-3"><a href="#cb47-3" tabindex="-1"></a><span class="op">&gt;</span>     for <span class="ex">temperature</span> in 25 30 37 40</span>
+<span id="cb47-4"><a href="#cb47-4" tabindex="-1"></a><span class="op">&gt;</span>     do</span>
+<span id="cb47-5"><a href="#cb47-5" tabindex="-1"></a><span class="op">&gt;</span>         mkdir <span class="va">$species</span><span class="ex">-</span><span class="va">$temperature</span></span>
+<span id="cb47-6"><a href="#cb47-6" tabindex="-1"></a><span class="op">&gt;</span>     done</span>
+<span id="cb47-7"><a href="#cb47-7" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 </div>
 </div>
@@ -1230,7 +1224,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution8" aria-expanded="false" aria-controls="collapseSolution8">
   <h4 class="accordion-header" id="headingSolution8">Show me the solution</h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
 <div class="accordion-body">
 <p>We have a nested loop, i.e. contained within another loop, so for
 each species in the outer loop, the inner loop (the nested loop)
@@ -1328,7 +1322,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/05-loop.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-11-10",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/06-script.html b/instructor/06-script.html
index 0c71f5e65..ce0a76a39 100644
--- a/instructor/06-script.html
+++ b/instructor/06-script.html
@@ -328,8 +328,8 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd alkanes</span>
-<span id="cb1-2"><a href="#cb1-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> cd alkanes</span>
+<span id="cb1-2"><a href="#cb1-2" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <p>The command <code>nano middle.sh</code> opens the file
 <code>middle.sh</code> within the text editor ‘nano’ (which runs within
@@ -351,7 +351,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -364,13 +364,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 <p>Sure enough, our script’s output is exactly what we would get if we
 ran that pipeline directly.</p>
-<div id="text-vs.-whatever" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="text-vs.-whatever" class="callout-inner">
-<h3 class="callout-title">Text vs. Whatever<a class="anchor" aria-label="anchor" href="#text-vs.-whatever"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="text-vs--whatever">Text vs. Whatever<a class="anchor" aria-label="anchor" href="#text-vs--whatever"></a></h3>
 <div class="callout-content">
 <p>We usually call programs like Microsoft Word or LibreOffice Writer
 “text editors”, but we need to be a bit more careful when it comes to
@@ -393,7 +392,7 @@ <h3 class="callout-title">Text vs. Whatever<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <p>Now, within “nano”, replace the text <code>octane.pdb</code> with the
 special variable called <code>$1</code>:</p>
@@ -404,7 +403,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh octane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh octane.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -419,7 +418,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -430,13 +429,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 ATOM     12  H           1      -0.048  -1.362  -0.205  1.00  0.00
 ATOM     13  H           1      -1.183   0.500  -1.412  1.00  0.00</code></pre>
 </div>
-<div id="double-quotes-around-arguments" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="double-quotes-around-arguments" class="callout-inner">
-<h3 class="callout-title">Double-Quotes Around Arguments<a class="anchor" aria-label="anchor" href="#double-quotes-around-arguments"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="double-quotes-around-arguments">Double-Quotes Around Arguments<a class="anchor" aria-label="anchor" href="#double-quotes-around-arguments"></a></h3>
 <div class="callout-content">
 <p>For the same reason that we put the loop variable inside
 double-quotes, in case the filename happens to contain any spaces, we
@@ -457,14 +455,14 @@ <h3 class="callout-title">Double-Quotes Around Arguments<a class="anchor" aria-l
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <pre class="source"><code>head -n "$2" "$1" | tail -n "$3"</code></pre>
 <p>We can now run:</p>
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 15 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 15 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -480,7 +478,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 20 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 20 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -498,7 +496,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <pre class="source"><code># Select lines from the middle of a file.
 # Usage: bash middle.sh filename end_line num_lines
@@ -515,7 +513,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
 </div>
 <p>because <code>wc -l</code> lists the number of lines in the files
 (recall that <code>wc</code> stands for ‘word count’, adding the
@@ -535,7 +533,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano sorted.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> nano sorted.sh</span></code></pre>
 </div>
 <pre class="source"><code># Sort files by their length.
 # Usage: bash sorted.sh one_or_more_filenames
@@ -543,7 +541,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash sorted.sh <span class="pp">*</span>.pdb ../creatures/<span class="pp">*</span>.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> bash sorted.sh <span class="pp">*</span>.pdb ../creatures/<span class="pp">*</span>.dat</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -601,16 +599,16 @@ <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script to find unique species in csv files where species is the second data field</span></span>
-<span id="cb25-2"><a href="#cb25-2" aria-hidden="true" tabindex="-1"></a><span class="co"># This script accepts any number of file names as command line arguments</span></span>
-<span id="cb25-3"><a href="#cb25-3" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb25-4"><a href="#cb25-4" aria-hidden="true" tabindex="-1"></a><span class="co"># Loop over all files</span></span>
-<span id="cb25-5"><a href="#cb25-5" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> file <span class="kw">in</span> <span class="va">$@</span></span>
-<span id="cb25-6"><a href="#cb25-6" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb25-7"><a href="#cb25-7" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="st">"Unique species in </span><span class="va">$file</span><span class="st">:"</span></span>
-<span id="cb25-8"><a href="#cb25-8" aria-hidden="true" tabindex="-1"></a>    <span class="co"># Extract species names</span></span>
-<span id="cb25-9"><a href="#cb25-9" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 2 <span class="va">$file</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span>
-<span id="cb25-10"><a href="#cb25-10" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="co"># Script to find unique species in csv files where species is the second data field</span></span>
+<span id="cb25-2"><a href="#cb25-2" tabindex="-1"></a><span class="co"># This script accepts any number of file names as command line arguments</span></span>
+<span id="cb25-3"><a href="#cb25-3" tabindex="-1"></a></span>
+<span id="cb25-4"><a href="#cb25-4" tabindex="-1"></a><span class="co"># Loop over all files</span></span>
+<span id="cb25-5"><a href="#cb25-5" tabindex="-1"></a><span class="cf">for</span> file <span class="kw">in</span> <span class="va">$@</span></span>
+<span id="cb25-6"><a href="#cb25-6" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb25-7"><a href="#cb25-7" tabindex="-1"></a>    <span class="bu">echo</span> <span class="st">"Unique species in </span><span class="va">$file</span><span class="st">:"</span></span>
+<span id="cb25-8"><a href="#cb25-8" tabindex="-1"></a>    <span class="co"># Extract species names</span></span>
+<span id="cb25-9"><a href="#cb25-9" tabindex="-1"></a>    <span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 2 <span class="va">$file</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span>
+<span id="cb25-10"><a href="#cb25-10" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 </div>
 </div>
@@ -624,7 +622,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> redo-figure-3.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> redo-figure-3.sh</span></code></pre>
 </div>
 <p>The file <code>redo-figure-3.sh</code> now contains:</p>
 <pre class="source"><code>297 bash goostats.sh NENE01729B.txt stats-NENE01729B.txt
@@ -649,7 +647,7 @@ <h3 class="callout-title">Why Record Commands in the History Before
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> recent.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> recent.sh</span></code></pre>
 </div>
 <p>the last command in the file is the <code>history</code> command
 itself, i.e., the shell has added <code>history</code> to the command
@@ -689,37 +687,37 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb29">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ../../north-pacific-gyre/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="ex">$</span> cd ../../north-pacific-gyre/</span></code></pre>
 </div>
 <p>She creates a file using <code>nano</code> …</p>
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano do-stats.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> nano do-stats.sh</span></code></pre>
 </div>
 <p>…which contains the following:</p>
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
-<span id="cb31-2"><a href="#cb31-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
-<span id="cb31-3"><a href="#cb31-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb31-4"><a href="#cb31-4" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
-<span id="cb31-5"><a href="#cb31-5" aria-hidden="true" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb31-6"><a href="#cb31-6" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
+<span id="cb31-2"><a href="#cb31-2" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
+<span id="cb31-3"><a href="#cb31-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb31-4"><a href="#cb31-4" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
+<span id="cb31-5"><a href="#cb31-5" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb31-6"><a href="#cb31-6" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <p>She saves this in a file called <code>do-stats.sh</code> so that she
 can now re-do the first stage of her analysis by typing:</p>
 <div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
 </div>
 <p>She can also do this:</p>
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt <span class="kw">|</span> <span class="fu">wc</span> <span class="at">-l</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt <span class="kw">|</span> <span class="fu">wc</span> <span class="at">-l</span></span></code></pre>
 </div>
 <p>so that the output is just the number of files processed rather than
 the names of the files that were processed.</p>
@@ -729,12 +727,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Calculate stats for Site A and Site B data files.</span></span>
-<span id="cb34-2"><a href="#cb34-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
-<span id="cb34-3"><a href="#cb34-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb34-4"><a href="#cb34-4" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
-<span id="cb34-5"><a href="#cb34-5" aria-hidden="true" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb34-6"><a href="#cb34-6" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="co"># Calculate stats for Site A and Site B data files.</span></span>
+<span id="cb34-2"><a href="#cb34-2" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
+<span id="cb34-3"><a href="#cb34-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb34-4"><a href="#cb34-4" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
+<span id="cb34-5"><a href="#cb34-5" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb34-6"><a href="#cb34-6" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <p>The advantage is that this always selects the right files: she
 doesn’t have to remember to exclude the ‘Z’ files. The disadvantage is
@@ -759,15 +757,15 @@ <h3 class="callout-title">Variables in Shell Scripts<a class="anchor" aria-label
 <div class="codewrapper sourceCode" id="cb35">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" aria-hidden="true" tabindex="-1"></a><span class="fu">head</span> <span class="at">-n</span> <span class="va">$2</span> <span class="va">$1</span></span>
-<span id="cb35-2"><a href="#cb35-2" aria-hidden="true" tabindex="-1"></a><span class="fu">tail</span> <span class="at">-n</span> <span class="va">$3</span> <span class="va">$1</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" tabindex="-1"></a><span class="fu">head</span> <span class="at">-n</span> <span class="va">$2</span> <span class="va">$1</span></span>
+<span id="cb35-2"><a href="#cb35-2" tabindex="-1"></a><span class="fu">tail</span> <span class="at">-n</span> <span class="va">$3</span> <span class="va">$1</span></span></code></pre>
 </div>
 <p>While you are in the <code>alkanes</code> directory, you type the
 following command:</p>
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash script.sh <span class="st">'*.pdb'</span> 1 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> bash script.sh <span class="st">'*.pdb'</span> 1 1</span></code></pre>
 </div>
 <p>Which of the following outputs would you expect to see?</p>
 <ol style="list-style-type: decimal"><li>All of the lines between the first and the last lines of each file
@@ -795,8 +793,8 @@ <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span>
-<span id="cb37-2"><a href="#cb37-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span>
+<span id="cb37-2"><a href="#cb37-2" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span></code></pre>
 </div>
 <p>The shell does not expand <code>'*.pdb'</code> because it is enclosed
 by quote marks. As such, the first argument to the script is
@@ -822,7 +820,7 @@ <h3 class="callout-title">Find the Longest File With a Given
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/alkanes pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/alkanes pdb</span></code></pre>
 </div>
 <p>would print the name of the <code>.pdb</code> file in
 <code>shell-lesson-data/exercise-data/alkanes</code> that has the most
@@ -831,7 +829,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/writing txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/writing txt</span></code></pre>
 </div>
 </div>
 </div>
@@ -846,13 +844,13 @@ <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb40">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Shell script which takes two arguments:</span></span>
-<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a><span class="co">#    1. a directory name</span></span>
-<span id="cb40-3"><a href="#cb40-3" aria-hidden="true" tabindex="-1"></a><span class="co">#    2. a file extension</span></span>
-<span id="cb40-4"><a href="#cb40-4" aria-hidden="true" tabindex="-1"></a><span class="co"># and prints the name of the file in that directory</span></span>
-<span id="cb40-5"><a href="#cb40-5" aria-hidden="true" tabindex="-1"></a><span class="co"># with the most lines which matches the file extension.</span></span>
-<span id="cb40-6"><a href="#cb40-6" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb40-7"><a href="#cb40-7" aria-hidden="true" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$1</span>/<span class="pp">*</span>.<span class="va">$2</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 2 <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" tabindex="-1"></a><span class="co"># Shell script which takes two arguments:</span></span>
+<span id="cb40-2"><a href="#cb40-2" tabindex="-1"></a><span class="co">#    1. a directory name</span></span>
+<span id="cb40-3"><a href="#cb40-3" tabindex="-1"></a><span class="co">#    2. a file extension</span></span>
+<span id="cb40-4"><a href="#cb40-4" tabindex="-1"></a><span class="co"># and prints the name of the file in that directory</span></span>
+<span id="cb40-5"><a href="#cb40-5" tabindex="-1"></a><span class="co"># with the most lines which matches the file extension.</span></span>
+<span id="cb40-6"><a href="#cb40-6" tabindex="-1"></a></span>
+<span id="cb40-7"><a href="#cb40-7" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$1</span>/<span class="pp">*</span>.<span class="va">$2</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 2 <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
 </div>
 <p>The first part of the pipeline, <code>wc -l $1/*.$2 | sort -n</code>,
 counts the lines in each file and sorts them numerically (largest last).
@@ -885,23 +883,23 @@ <h3 class="callout-title">Script Reading Comprehension<a class="anchor" aria-lab
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script 1</span></span>
-<span id="cb41-2"><a href="#cb41-2" aria-hidden="true" tabindex="-1"></a><span class="bu">echo</span> <span class="pp">*</span>.<span class="pp">*</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="co"># Script 1</span></span>
+<span id="cb41-2"><a href="#cb41-2" tabindex="-1"></a><span class="bu">echo</span> <span class="pp">*</span>.<span class="pp">*</span></span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script 2</span></span>
-<span id="cb42-2"><a href="#cb42-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> filename <span class="kw">in</span> <span class="va">$1</span> <span class="va">$2</span> <span class="va">$3</span></span>
-<span id="cb42-3"><a href="#cb42-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb42-4"><a href="#cb42-4" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$filename</span></span>
-<span id="cb42-5"><a href="#cb42-5" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="co"># Script 2</span></span>
+<span id="cb42-2"><a href="#cb42-2" tabindex="-1"></a><span class="cf">for</span> filename <span class="kw">in</span> <span class="va">$1</span> <span class="va">$2</span> <span class="va">$3</span></span>
+<span id="cb42-3"><a href="#cb42-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb42-4"><a href="#cb42-4" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$filename</span></span>
+<span id="cb42-5"><a href="#cb42-5" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script 3</span></span>
-<span id="cb43-2"><a href="#cb43-2" aria-hidden="true" tabindex="-1"></a><span class="bu">echo</span> <span class="va">$@</span>.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="co"># Script 3</span></span>
+<span id="cb43-2"><a href="#cb43-2" tabindex="-1"></a><span class="bu">echo</span> <span class="va">$@</span>.pdb</span></code></pre>
 </div>
 </div>
 </div>
@@ -949,26 +947,26 @@ <h3 class="callout-title">Debugging Scripts<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
-<span id="cb45-2"><a href="#cb45-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
-<span id="cb45-3"><a href="#cb45-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb45-4"><a href="#cb45-4" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datfile</span></span>
-<span id="cb45-5"><a href="#cb45-5" aria-hidden="true" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb45-6"><a href="#cb45-6" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
+<span id="cb45-2"><a href="#cb45-2" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
+<span id="cb45-3"><a href="#cb45-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb45-4"><a href="#cb45-4" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datfile</span></span>
+<span id="cb45-5"><a href="#cb45-5" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb45-6"><a href="#cb45-6" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <p>When you run it from the <code>north-pacific-gyre</code>
 directory:</p>
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="ex">$</span> bash do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
 </div>
 <p>the output is blank. To figure out why, re-run the script using the
 <code>-x</code> option:</p>
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash <span class="at">-x</span> do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> bash <span class="at">-x</span> do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
 </div>
 <p>What is the output showing you? Which line is responsible for the
 error?</p>
@@ -1076,7 +1074,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/06-script.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-08-05",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/07-find.html b/instructor/07-find.html
index 23b25f0d6..76b733f4b 100644
--- a/instructor/07-find.html
+++ b/instructor/07-find.html
@@ -321,9 +321,9 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd</span>
-<span id="cb1-2"><a href="#cb1-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data/writing</span>
-<span id="cb1-3"><a href="#cb1-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cat haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> cd</span>
+<span id="cb1-2"><a href="#cb1-2" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data/writing</span>
+<span id="cb1-3"><a href="#cb1-3" tabindex="-1"></a><span class="ex">$</span> cat haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -344,7 +344,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep not haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> grep not haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -367,7 +367,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep The haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> grep The haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -386,7 +386,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> The haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> The haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -400,7 +400,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> <span class="st">"is not"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> <span class="st">"is not"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -417,7 +417,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="st">"it"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="st">"it"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -435,7 +435,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -448,7 +448,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-i</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-i</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -463,7 +463,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-v</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-v</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -486,7 +486,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-r</span> Yesterday .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-r</span> Yesterday .</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -501,7 +501,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">--help</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">--help</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -561,13 +561,12 @@ <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </div>
 </div>
 </div>
-<div id="wildcards" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="wildcards" class="callout-inner">
-<h3 class="callout-title">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="wildcards">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a></h3>
 <div class="callout-content">
 <p><code>grep</code>‘s real power doesn’t come from its options, though;
 it comes from the fact that patterns can include wildcards. (The
@@ -580,7 +579,7 @@ <h3 class="callout-title">Wildcards<a class="anchor" aria-label="anchor" href="#
 <div class="codewrapper sourceCode" id="cb24">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-E</span> <span class="st">"^.o"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-E</span> <span class="st">"^.o"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -631,13 +630,13 @@ <h3 class="callout-title">Tracking a Species<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> : <span class="at">-f</span> 2</span>
-<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span></span>
-<span id="cb28-3"><a href="#cb28-3" aria-hidden="true" tabindex="-1"></a><span class="kw">|</span></span>
-<span id="cb28-4"><a href="#cb28-4" aria-hidden="true" tabindex="-1"></a><span class="fu">grep</span> <span class="at">-w</span> <span class="va">$1</span> <span class="at">-r</span> <span class="va">$2</span></span>
-<span id="cb28-5"><a href="#cb28-5" aria-hidden="true" tabindex="-1"></a><span class="kw">|</span></span>
-<span id="cb28-6"><a href="#cb28-6" aria-hidden="true" tabindex="-1"></a><span class="va">$1</span><span class="ex">.txt</span></span>
-<span id="cb28-7"><a href="#cb28-7" aria-hidden="true" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 1,3</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> : <span class="at">-f</span> 2</span>
+<span id="cb28-2"><a href="#cb28-2" tabindex="-1"></a><span class="op">&gt;</span></span>
+<span id="cb28-3"><a href="#cb28-3" tabindex="-1"></a><span class="kw">|</span></span>
+<span id="cb28-4"><a href="#cb28-4" tabindex="-1"></a><span class="fu">grep</span> <span class="at">-w</span> <span class="va">$1</span> <span class="at">-r</span> <span class="va">$2</span></span>
+<span id="cb28-5"><a href="#cb28-5" tabindex="-1"></a><span class="kw">|</span></span>
+<span id="cb28-6"><a href="#cb28-6" tabindex="-1"></a><span class="va">$1</span><span class="ex">.txt</span></span>
+<span id="cb28-7"><a href="#cb28-7" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 1,3</span></code></pre>
 </div>
 <p>Hint: use <code>man grep</code> to look for how to grep text
 recursively in a directory and <code>man cut</code> to select more than
@@ -663,7 +662,7 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash count-species.sh bear .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> bash count-species.sh bear .</span></code></pre>
 </div>
 </div>
 </div>
@@ -763,7 +762,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> find .</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -799,7 +798,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> d</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> d</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -816,7 +815,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> f</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> f</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -839,7 +838,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb40">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="pp">*</span>.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="pp">*</span>.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -854,7 +853,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> numbers.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> numbers.txt</span></code></pre>
 </div>
 <p><code>find</code> did what we asked; we just asked for the wrong
 thing.</p>
@@ -866,7 +865,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="st">"*.txt"</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="st">"*.txt"</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -875,13 +874,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <span><span class="va">.</span><span class="op">/</span><span class="va">writing</span><span class="op">/</span><span class="va">haiku.txt</span></span>
 <span><span class="va">.</span><span class="op">/</span><span class="va">numbers.txt</span></span></code></pre>
 </div>
-<div id="listing-vs.-finding" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="listing-vs.-finding" class="callout-inner">
-<h3 class="callout-title">Listing vs. Finding<a class="anchor" aria-label="anchor" href="#listing-vs.-finding"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="listing-vs--finding">Listing vs. Finding<a class="anchor" aria-label="anchor" href="#listing-vs--finding"></a></h3>
 <div class="callout-content">
 <p><code>ls</code> and <code>find</code> can be made to do similar
 things given the right options, but under normal circumstances,
@@ -900,7 +898,7 @@ <h3 class="callout-title">Listing vs. Finding<a class="anchor" aria-label="anch
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -920,7 +918,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> ./writing/LittleWomen.txt ./writing/haiku.txt ./numbers.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> ./writing/LittleWomen.txt ./writing/haiku.txt ./numbers.txt</span></code></pre>
 </div>
 <p>which is what we wanted. This expansion is exactly what the shell
 does when it expands wildcards like <code>*</code> and <code>?</code>,
@@ -934,7 +932,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb48">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="st">"searching"</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="st">"searching"</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -984,13 +982,12 @@ <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 </div>
 </div>
 </div>
-<div id="binary-files" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="binary-files" class="callout-inner">
-<h3 class="callout-title">Binary Files<a class="anchor" aria-label="anchor" href="#binary-files"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="binary-files">Binary Files<a class="anchor" aria-label="anchor" href="#binary-files"></a></h3>
 <div class="callout-content">
 <p>We have focused exclusively on finding patterns in text files. What
 if your data is stored as images, in databases, or in some other
@@ -1035,7 +1032,7 @@ <h3 class="callout-title">
 <div class="codewrapper sourceCode" id="cb50">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" aria-hidden="true" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.dat"</span><span class="va">)</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.dat"</span><span class="va">)</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
 </div>
 </div>
 </div>
@@ -1142,7 +1139,7 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/07-find.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-11-09",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/404.html b/instructor/404.html
index 521768e6c..22648b169 100644
--- a/instructor/404.html
+++ b/instructor/404.html
@@ -319,8 +319,8 @@ <h1>Page not found</h1>
   "url": "https://swcarpentry.github.io/shell-novice/instructor/404.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/404.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-02-27",
-  "datePublished": "2024-02-27"
+  "dateModified": "2024-03-05",
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/CODE_OF_CONDUCT.html b/instructor/CODE_OF_CONDUCT.html
index a66f27581..7ced71344 100644
--- a/instructor/CODE_OF_CONDUCT.html
+++ b/instructor/CODE_OF_CONDUCT.html
@@ -339,7 +339,7 @@ <h1>Contributor Code of Conduct</h1>
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/CODE_OF_CONDUCT.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-05-02",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/LICENSE.html b/instructor/LICENSE.html
index ac00ab197..ab1cac166 100644
--- a/instructor/LICENSE.html
+++ b/instructor/LICENSE.html
@@ -390,7 +390,7 @@ <h1>Licenses</h1>
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/LICENSE.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-05-02",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/aio.html b/instructor/aio.html
index ba69a789b..533e0437d 100644
--- a/instructor/aio.html
+++ b/instructor/aio.html
@@ -410,7 +410,7 @@ <h3 id="the-shell">The Shell<a class="anchor" aria-label="anchor" href="#the-she
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span></span></code></pre>
 </div>
 <p>The shell typically uses <code>$</code> as the prompt, but may use a
 different symbol. In the examples for this lesson, we’ll show the prompt
@@ -430,7 +430,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb2">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="ex">nelle@localhost</span> $</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" tabindex="-1"></a><span class="ex">nelle@localhost</span> $</span></code></pre>
 </div>
 <p>The prompt might even include more than this. Do not worry if your
 prompt is not just a short <code>$</code>. This lesson does not depend
@@ -443,7 +443,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -451,12 +451,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <pre class="output" tabindex="0"><code>Desktop     Downloads   Movies      Pictures
 Documents   Library     Music       Public</code></pre>
 </div>
-<div id="command-not-found" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="command-not-found" class="callout-inner">
-<h3 class="callout-title">Command not found<a class="anchor" aria-label="anchor" href="#command-not-found"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="command-not-found">Command not found<a class="anchor" aria-label="anchor" href="#command-not-found"></a>
 </h3>
 <div class="callout-content">
 <p>If the shell can’t find a program whose name is the command you
@@ -464,7 +464,7 @@ <h3 class="callout-title">Command not found<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ks</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> ks</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -587,7 +587,7 @@ <h3 class="card-title">Objectives</h3>
   <h3 class="accordion-header" id="headingInstructor1">
 <div class="note-square"><i aria-hidden="true" class="callout-icon" data-feather="edit-2"></i></div>Instructor Note</h3>
 </button>
-<div id="collapseInstructor1" class="accordion-collapse collapse" data-bs-parent="#accordionInstructor1" aria-labelledby="headingInstructor1">
+<div id="collapseInstructor1" class="accordion-collapse collapse" aria-labelledby="headingInstructor1" data-bs-parent="#accordionInstructor1">
 <div class="accordion-body">
 <p>Introducing and navigating the filesystem in the shell (covered in <a href="02-filedir.html">Navigating Files and Directories</a> section) can
 be confusing. You may have both terminal and GUI file explorer open side
@@ -615,7 +615,7 @@ <h3 class="accordion-header" id="headingInstructor1">
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -624,12 +624,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 <p>Here, the computer’s response is <code>/Users/nelle</code>, which is
 Nelle’s <strong>home directory</strong>:</p>
-<div id="home-directory-variation" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="home-directory-variation" class="callout-inner">
-<h3 class="callout-title">Home Directory Variation<a class="anchor" aria-label="anchor" href="#home-directory-variation"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="home-directory-variation">Home Directory Variation<a class="anchor" aria-label="anchor" href="#home-directory-variation"></a>
 </h3>
 <div class="callout-content">
 <p>The home directory path will look different on different operating
@@ -669,12 +669,12 @@ <h3 class="callout-title">Home Directory Variation<a class="anchor" aria-label="
 first part of its name. Similarly, we know that <code>/Users</code> is
 stored inside the root directory <code>/</code> because its name begins
 with <code>/</code>.</p>
-<div id="slashes" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="slashes" class="callout-inner">
-<h3 class="callout-title">Slashes<a class="anchor" aria-label="anchor" href="#slashes"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="slashes">Slashes<a class="anchor" aria-label="anchor" href="#slashes"></a>
 </h3>
 <div class="callout-content">
 <p>Notice that there are two meanings for the <code>/</code> character.
@@ -700,7 +700,7 @@ <h3 class="callout-title">Slashes<a class="anchor" aria-label="anchor" href="#sl
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -727,7 +727,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -739,12 +739,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <strong>sub-directories</strong>. Any names in the output that don’t
 have a classification symbol are <strong>files</strong> in the current
 working directory.</p>
-<div id="clearing-your-terminal" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="clearing-your-terminal" class="callout-inner">
-<h3 class="callout-title">Clearing your terminal<a class="anchor" aria-label="anchor" href="#clearing-your-terminal"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="clearing-your-terminal">Clearing your terminal<a class="anchor" aria-label="anchor" href="#clearing-your-terminal"></a>
 </h3>
 <div class="callout-content">
 <p>If your screen gets too cluttered, you can clear your terminal using
@@ -768,7 +768,7 @@ <h3 id="getting-help">Getting help<a class="anchor" aria-label="anchor" href="#g
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
 </div>
 <ol start="2" style="list-style-type: decimal">
 <li>We can read its manual with <code>man</code> (available on Linux and
@@ -777,15 +777,15 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb8">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
 </div>
 <p>We’ll describe both ways next.</p>
-<div id="help-for-built-in-commands" class="callout callout">
+<div id="callout4" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="help-for-built-in-commands" class="callout-inner">
-<h3 class="callout-title">Help for built-in commands<a class="anchor" aria-label="anchor" href="#help-for-built-in-commands"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="help-for-built-in-commands">Help for built-in commands<a class="anchor" aria-label="anchor" href="#help-for-built-in-commands"></a>
 </h3>
 <div class="callout-content">
 <p>Some commands are built in to the Bash shell, rather than existing as
@@ -806,7 +806,7 @@ <h4 id="the---help-option">The <code>--help</code> option<a class="anchor" aria-
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">--help</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -837,12 +837,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
   -F, --classify             append indicator (one of */=&gt;@|) to entries
 ...        ...        ...</code></pre>
 </div>
-<div id="unsupported-command-line-options" class="callout callout">
+<div id="callout5" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="unsupported-command-line-options" class="callout-inner">
-<h3 class="callout-title">Unsupported command-line options<a class="anchor" aria-label="anchor" href="#unsupported-command-line-options"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="unsupported-command-line-options">Unsupported command-line options<a class="anchor" aria-label="anchor" href="#unsupported-command-line-options"></a>
 </h3>
 <div class="callout-content">
 <p>If you try to use an option that is not supported, <code>ls</code>
@@ -850,7 +850,7 @@ <h3 class="callout-title">Unsupported command-line options<a class="anchor" aria
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-j</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-j</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -869,7 +869,7 @@ <h4 id="the-man-command">The <code>man</code> command<a class="anchor" aria-labe
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> man ls</span></code></pre>
 </div>
 <p>This command will turn your terminal into a page with a description
 of the <code>ls</code> command and its options.</p>
@@ -883,12 +883,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <kbd>Shift</kbd>+<kbd>N</kbd> (for moving backward).</p>
 <p>To <strong>quit</strong> the <code>man</code> pages, press
 <kbd>Q</kbd>.</p>
-<div id="manual-pages-on-the-web" class="callout callout">
+<div id="callout6" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="manual-pages-on-the-web" class="callout-inner">
-<h3 class="callout-title">Manual pages on the web<a class="anchor" aria-label="anchor" href="#manual-pages-on-the-web"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="manual-pages-on-the-web">Manual pages on the web<a class="anchor" aria-label="anchor" href="#manual-pages-on-the-web"></a>
 </h3>
 <div class="callout-content">
 <p>Of course, there is a third way to access help for commands:
@@ -924,7 +924,7 @@ <h3 class="callout-title">Exploring More<code>ls</code>Options<a class="anchor"
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>The <code>-l</code> option makes <code>ls</code> use a
 <strong>l</strong>ong listing format, showing not only the
@@ -960,7 +960,7 @@ <h3 class="callout-title">Listing in Reverse Chronological Order<a class="anchor
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>The most recently changed file is listed last when using
 <code>-rt</code>. This can be very useful for finding your most recent
@@ -985,7 +985,7 @@ <h3 id="exploring-other-directories">Exploring Other Directories<a class="anchor
 <div class="codewrapper sourceCode" id="cb14">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb14-1"><a href="#cb14-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb14-1"><a href="#cb14-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1016,7 +1016,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb16">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop/shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> Desktop/shell-lesson-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1038,9 +1038,9 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop</span>
-<span id="cb18-2"><a href="#cb18-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span>
-<span id="cb18-3"><a href="#cb18-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> cd Desktop</span>
+<span id="cb18-2"><a href="#cb18-2" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span>
+<span id="cb18-3"><a href="#cb18-3" tabindex="-1"></a><span class="ex">$</span> cd exercise-data</span></code></pre>
 </div>
 <p>These commands will move us from our home directory into our Desktop
 directory, then into the <code>shell-lesson-data</code> directory, then
@@ -1057,7 +1057,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1067,7 +1067,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1080,7 +1080,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb23">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" tabindex="-1"></a><span class="ex">$</span> cd shell-lesson-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1097,7 +1097,7 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ..</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="ex">$</span> cd ..</span></code></pre>
 </div>
 <p><code>..</code> is a special directory name meaning “the directory
 containing this one”, or more succinctly, the <strong>parent</strong> of
@@ -1107,7 +1107,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1120,7 +1120,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> <span class="at">-a</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> <span class="at">-a</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1138,12 +1138,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <p>Note that in most command line tools, multiple options can be
 combined with a single <code>-</code> and no spaces between the options;
 <code>ls -F -a</code> is equivalent to <code>ls -Fa</code>.</p>
-<div id="other-hidden-files" class="callout callout">
+<div id="callout7" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="other-hidden-files" class="callout-inner">
-<h3 class="callout-title">Other Hidden Files<a class="anchor" aria-label="anchor" href="#other-hidden-files"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="other-hidden-files">Other Hidden Files<a class="anchor" aria-label="anchor" href="#other-hidden-files"></a>
 </h3>
 <div class="callout-content">
 <p>In addition to the hidden directories <code>..</code> and
@@ -1166,14 +1166,14 @@ <h3 class="callout-title">Other Hidden Files<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> cd</span></code></pre>
 </div>
 <p>How can you check what happened? <code>pwd</code> gives us the
 answer!</p>
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1190,7 +1190,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data</span></code></pre>
 </div>
 <p>Check that we’ve moved to the right place by running <code>pwd</code>
 and <code>ls -F</code>.</p>
@@ -1216,7 +1216,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1226,16 +1226,16 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd /Users/nelle/Desktop/shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> cd /Users/nelle/Desktop/shell-lesson-data</span></code></pre>
 </div>
 <p>Run <code>pwd</code> and <code>ls -F</code> to ensure that we’re in
 the directory we expect.</p>
-<div id="two-more-shortcuts" class="callout callout">
+<div id="callout8" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="two-more-shortcuts" class="callout-inner">
-<h3 class="callout-title">Two More Shortcuts<a class="anchor" aria-label="anchor" href="#two-more-shortcuts"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="two-more-shortcuts">Two More Shortcuts<a class="anchor" aria-label="anchor" href="#two-more-shortcuts"></a>
 </h3>
 <div class="callout-content">
 <p>The shell interprets a tilde (<code>~</code>) character at the start
@@ -1260,20 +1260,20 @@ <h3 class="callout-title">Two More Shortcuts<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span></code></pre>
 </div>
 <p>Then <code>cd</code> into the <code>exercise-data/creatures</code>
 directory</p>
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/creatures</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/creatures</span></code></pre>
 </div>
 <p>Now if you run</p>
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd <span class="at">-</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> cd <span class="at">-</span></span></code></pre>
 </div>
 <p>you’ll see you’re back in <code>~/Desktop/shell-lesson-data</code>.
 Run <code>cd -</code> again and you’re back in
@@ -1311,7 +1311,7 @@ <h3 class="callout-title">Absolute vs Relative Paths<a class="anchor" aria-label
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>No: <code>.</code> stands for the current directory.</li>
@@ -1357,7 +1357,7 @@ <h3 class="callout-title">Relative Path Resolution<a class="anchor" aria-label="
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>No: there <em>is</em> a directory <code>backup</code> in
@@ -1403,7 +1403,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5">Show me the solution</h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>No: <code>pwd</code> is not the name of a directory.</li>
@@ -1426,7 +1426,7 @@ <h4 class="accordion-header" id="headingSolution5">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
 </div>
 <figure><img src="../fig/shell_command_syntax.svg" alt="General syntax of a shell command" class="figure mx-auto d-block"></figure><p><code>ls</code> is the <strong>command</strong>, with an
 <strong>option</strong> <code>-F</code> and an <strong>argument</strong>
@@ -1452,8 +1452,8 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span>
-<span id="cb42-2"><a href="#cb42-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-s</span> exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data</span>
+<span id="cb42-2"><a href="#cb42-2" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-s</span> exercise-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1468,7 +1468,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb44">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-S</span> exercise-data</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-S</span> exercise-data</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1482,7 +1482,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> /</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1491,12 +1491,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 Library/              Users/
 Network/              Volumes/</code></pre>
 </div>
-<div id="when-to-use-short-or-long-options" class="callout callout">
+<div id="callout9" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="when-to-use-short-or-long-options" class="callout-inner">
-<h3 class="callout-title">When to use short or long options<a class="anchor" aria-label="anchor" href="#when-to-use-short-or-long-options"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="when-to-use-short-or-long-options">When to use short or long options<a class="anchor" aria-label="anchor" href="#when-to-use-short-or-long-options"></a>
 </h3>
 <div class="callout-content">
 <p>When options exist as both short and long options:</p>
@@ -1530,7 +1530,7 @@ <h3 id="nelles-pipeline-organizing-files">Nelle’s Pipeline: Organizing Files<a
 <div class="codewrapper sourceCode" id="cb48">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
 </div>
 <p>This command is a lot to type, but she can let the shell do most of
 the work through what is called <strong>tab completion</strong>. If she
@@ -1538,14 +1538,14 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb49">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls nor</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" tabindex="-1"></a><span class="ex">$</span> ls nor</span></code></pre>
 </div>
 <p>and then presses <kbd>Tab</kbd> (the tab key on her keyboard), the
 shell automatically completes the directory name for her:</p>
 <div class="codewrapper sourceCode" id="cb50">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/</span></code></pre>
 </div>
 <p>Pressing <kbd>Tab</kbd> again does nothing, since there are multiple
 possibilities; pressing <kbd>Tab</kbd> twice brings up a list of all the
@@ -1556,15 +1556,15 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb51">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb51-1"><a href="#cb51-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/goo</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb51-1"><a href="#cb51-1" tabindex="-1"></a><span class="ex">$</span> ls north-pacific-gyre/goo</span></code></pre>
 </div>
 <p>To see all of those files, she can press <kbd>Tab</kbd> twice
 more.</p>
 <div class="codewrapper sourceCode" id="cb52">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" aria-hidden="true" tabindex="-1"></a><span class="fu">ls</span> north-pacific-gyre/goo</span>
-<span id="cb52-2"><a href="#cb52-2" aria-hidden="true" tabindex="-1"></a><span class="ex">goodiff.sh</span>   goostats.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" tabindex="-1"></a><span class="fu">ls</span> north-pacific-gyre/goo</span>
+<span id="cb52-2"><a href="#cb52-2" tabindex="-1"></a><span class="ex">goodiff.sh</span>   goostats.sh</span></code></pre>
 </div>
 <p>This is called <strong>tab completion</strong>, and we will see it in
 many other tools as we go on.</p>
@@ -1664,7 +1664,7 @@ <h3 id="step-one-see-where-we-are-and-what-we-already-have">Step one: see where
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1676,8 +1676,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/writing/</span>
-<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> cd exercise-data/writing/</span>
+<span id="cb3-2"><a href="#cb3-2" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1693,7 +1693,7 @@ <h3 id="create-a-directory">Create a directory<a class="anchor" aria-label="anch
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> mkdir thesis</span></code></pre>
 </div>
 <p>As you might guess from its name, <code>mkdir</code> means ‘make
 directory’. Since <code>thesis</code> is a relative path (i.e., does not
@@ -1702,7 +1702,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb6">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1714,7 +1714,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb8">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> thesis</span></code></pre>
 </div>
 <p>Note that <code>mkdir</code> is not limited to creating single
 directories one at a time. The <code>-p</code> option allows
@@ -1723,7 +1723,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> ../project/data ../project/results</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> ../project/data ../project/results</span></code></pre>
 </div>
 <p>The <code>-R</code> option to the <code>ls</code> command will list
 all nested subdirectories within a directory. Let’s use
@@ -1732,7 +1732,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-FR</span> ../project</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-FR</span> ../project</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1744,12 +1744,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 
 ../project/results:</code></pre>
 </div>
-<div id="two-ways-of-doing-the-same-thing" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="two-ways-of-doing-the-same-thing" class="callout-inner">
-<h3 class="callout-title">Two ways of doing the same thing<a class="anchor" aria-label="anchor" href="#two-ways-of-doing-the-same-thing"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="two-ways-of-doing-the-same-thing">Two ways of doing the same thing<a class="anchor" aria-label="anchor" href="#two-ways-of-doing-the-same-thing"></a>
 </h3>
 <div class="callout-content">
 <p>Using the shell to create a directory is no different than using a
@@ -1761,12 +1761,12 @@ <h3 class="callout-title">Two ways of doing the same thing<a class="anchor" aria
 </div>
 </div>
 </div>
-<div id="good-names-for-files-and-directories" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="good-names-for-files-and-directories" class="callout-inner">
-<h3 class="callout-title">Good names for files and directories<a class="anchor" aria-label="anchor" href="#good-names-for-files-and-directories"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="good-names-for-files-and-directories">Good names for files and directories<a class="anchor" aria-label="anchor" href="#good-names-for-files-and-directories"></a>
 </h3>
 <div class="callout-content">
 <p>Complicated names of files and directories can make your life painful
@@ -1828,15 +1828,15 @@ <h3 id="create-a-text-file">Create a text file<a class="anchor" aria-label="anch
 <div class="codewrapper sourceCode" id="cb12">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd thesis</span>
-<span id="cb12-2"><a href="#cb12-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano draft.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" tabindex="-1"></a><span class="ex">$</span> cd thesis</span>
+<span id="cb12-2"><a href="#cb12-2" tabindex="-1"></a><span class="ex">$</span> nano draft.txt</span></code></pre>
 </div>
-<div id="which-editor" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="which-editor" class="callout-inner">
-<h3 class="callout-title">Which Editor?<a class="anchor" aria-label="anchor" href="#which-editor"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="which-editor">Which Editor?<a class="anchor" aria-label="anchor" href="#which-editor"></a>
 </h3>
 <div class="callout-content">
 <p>When we say, ‘<code>nano</code> is a text editor’ we really do mean
@@ -1869,12 +1869,12 @@ <h3 class="callout-title">Which Editor?<a class="anchor" aria-label="anchor" hre
 to accept the suggested default of <code>draft.txt</code>.</p>
 <p>Once our file is saved, we can use <kbd>Ctrl</kbd>+<kbd>X</kbd> to
 quit the editor and return to the shell.</p>
-<div id="control-ctrl-or-key" class="callout callout">
+<div id="callout4" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="control-ctrl-or-key" class="callout-inner">
-<h3 class="callout-title">Control, Ctrl, or ^ Key<a class="anchor" aria-label="anchor" href="#control-ctrl-or-key"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="control-ctrl-or-key">Control, Ctrl, or ^ Key<a class="anchor" aria-label="anchor" href="#control-ctrl-or-key"></a>
 </h3>
 <div class="callout-content">
 <p>The Control key is also called the ‘Ctrl’ key. There are various ways
@@ -1902,7 +1902,7 @@ <h3 class="callout-title">Control, Ctrl, or ^ Key<a class="anchor" aria-label="a
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1922,7 +1922,7 @@ <h3 class="callout-title">Creating Files a Different Way<a class="anchor" aria-l
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> touch my_file.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> touch my_file.txt</span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li><p>What did the <code>touch</code> command do? When you look at your
@@ -1977,17 +1977,17 @@ <h3 class="callout-title">Creating Files a Different Way<em>(continued)</em><a c
 <div class="codewrapper sourceCode" id="cb16">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm my_file.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" tabindex="-1"></a><span class="ex">$</span> rm my_file.txt</span></code></pre>
 </div>
 </div>
 </div>
 </div>
-<div id="whats-in-a-name" class="callout callout">
+<div id="callout5" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="whats-in-a-name" class="callout-inner">
-<h3 class="callout-title">What’s In A Name?<a class="anchor" aria-label="anchor" href="#whats-in-a-name"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="whats-in-a-name">What’s In A Name?<a class="anchor" aria-label="anchor" href="#whats-in-a-name"></a>
 </h3>
 <div class="callout-content">
 <p>You may have noticed that all of Nelle’s files are named ‘something
@@ -2024,7 +2024,7 @@ <h3 class="callout-title">What’s In A Name?<a class="anchor" aria-label="ancho
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data/exercise-data/writing</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">$</span> cd ~/Desktop/shell-lesson-data/exercise-data/writing</span></code></pre>
 </div>
 <p>In our <code>thesis</code> directory we have a file
 <code>draft.txt</code> which isn’t a particularly informative name, so
@@ -2033,7 +2033,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv thesis/draft.txt thesis/quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> mv thesis/draft.txt thesis/quotes.txt</span></code></pre>
 </div>
 <p>The first argument tells <code>mv</code> what we’re ‘moving’, while
 the second is where it’s to go. In this case, we’re moving
@@ -2044,7 +2044,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2069,7 +2069,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv thesis/quotes.txt .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">$</span> mv thesis/quotes.txt .</span></code></pre>
 </div>
 <p>The effect is to move the file from the directory it was in to the
 current working directory. <code>ls</code> now shows us that
@@ -2077,7 +2077,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> ls thesis</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2090,7 +2090,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb24">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis/quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> ls thesis/quotes.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2105,7 +2105,7 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2127,18 +2127,18 @@ <h3 class="callout-title">Moving Files to a new folder<a class="anchor" aria-lab
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span>
-<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">analyzed/</span> raw/</span>
-<span id="cb28-3"><a href="#cb28-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> analyzed</span>
-<span id="cb28-4"><a href="#cb28-4" aria-hidden="true" tabindex="-1"></a><span class="ex">fructose.dat</span> glucose.dat maltose.dat sucrose.dat</span>
-<span id="cb28-5"><a href="#cb28-5" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd analyzed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span>
+<span id="cb28-2"><a href="#cb28-2" tabindex="-1"></a> <span class="ex">analyzed/</span> raw/</span>
+<span id="cb28-3"><a href="#cb28-3" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span> analyzed</span>
+<span id="cb28-4"><a href="#cb28-4" tabindex="-1"></a><span class="ex">fructose.dat</span> glucose.dat maltose.dat sucrose.dat</span>
+<span id="cb28-5"><a href="#cb28-5" tabindex="-1"></a><span class="ex">$</span> cd analyzed</span></code></pre>
 </div>
 <p>Fill in the blanks to move these files to the <code>raw/</code>
 folder (i.e. the one she forgot to put them in)</p>
 <div class="codewrapper sourceCode" id="cb29">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ____/____</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ____/____</span></code></pre>
 </div>
 </div>
 </div>
@@ -2153,7 +2153,7 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ../raw</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> mv sucrose.dat maltose.dat ../raw</span></code></pre>
 </div>
 <p>Recall that <code>..</code> refers to the parent directory (i.e. one
 above the current directory) and that <code>.</code> refers to the
@@ -2173,8 +2173,8 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp quotes.txt thesis/quotations.txt</span>
-<span id="cb31-2"><a href="#cb31-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt thesis/quotations.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="ex">$</span> cp quotes.txt thesis/quotations.txt</span>
+<span id="cb31-2"><a href="#cb31-2" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt thesis/quotations.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2186,14 +2186,14 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="at">-r</span> thesis thesis_backup</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="at">-r</span> thesis thesis_backup</span></code></pre>
 </div>
 <p>We can check the result by listing the contents of both the
 <code>thesis</code> and <code>thesis_backup</code> directory:</p>
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls thesis thesis_backup</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> ls thesis thesis_backup</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2211,8 +2211,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp thesis thesis_backup</span>
-<span id="cb36-2"><a href="#cb36-2" aria-hidden="true" tabindex="-1"></a><span class="ex">cp:</span> <span class="at">-r</span> not specified<span class="kw">;</span> <span class="ex">omitting</span> directory <span class="st">'thesis'</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> cp thesis thesis_backup</span>
+<span id="cb36-2"><a href="#cb36-2" tabindex="-1"></a><span class="ex">cp:</span> <span class="at">-r</span> not specified<span class="kw">;</span> <span class="ex">omitting</span> directory <span class="st">'thesis'</span></span></code></pre>
 </div>
 <div id="renaming-files" class="callout challenge">
 <div class="callout-square">
@@ -2271,7 +2271,7 @@ <h3 class="callout-title">Moving and Copying<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> pwd</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2281,7 +2281,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2291,10 +2291,10 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir recombined</span>
-<span id="cb41-2"><a href="#cb41-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mv proteins.dat recombined/</span>
-<span id="cb41-3"><a href="#cb41-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp recombined/proteins.dat ../proteins-saved.dat</span>
-<span id="cb41-4"><a href="#cb41-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="ex">$</span> mkdir recombined</span>
+<span id="cb41-2"><a href="#cb41-2" tabindex="-1"></a><span class="ex">$</span> mv proteins.dat recombined/</span>
+<span id="cb41-3"><a href="#cb41-3" tabindex="-1"></a><span class="ex">$</span> cp recombined/proteins.dat ../proteins-saved.dat</span>
+<span id="cb41-4"><a href="#cb41-4" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li><code>proteins-saved.dat recombined</code></li>
@@ -2349,25 +2349,25 @@ <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> rm quotes.txt</span></code></pre>
 </div>
 <p>We can confirm the file has gone using <code>ls</code>:</p>
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="ex">$</span> ls quotes.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="error" tabindex="0"><code>ls: cannot access 'quotes.txt': No such file or directory</code></pre>
 </div>
-<div id="deleting-is-forever" class="callout callout">
+<div id="callout6" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="deleting-is-forever" class="callout-inner">
-<h3 class="callout-title">Deleting Is Forever<a class="anchor" aria-label="anchor" href="#deleting-is-forever"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="deleting-is-forever">Deleting Is Forever<a class="anchor" aria-label="anchor" href="#deleting-is-forever"></a>
 </h3>
 <div class="callout-content">
 <p>The Unix shell doesn’t have a trash bin that we can recover deleted
@@ -2421,7 +2421,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="ex">$</span> rm thesis</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2436,7 +2436,7 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb48">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> rm <span class="at">-r</span> thesis</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" tabindex="-1"></a><span class="ex">$</span> rm <span class="at">-r</span> thesis</span></code></pre>
 </div>
 <p>Given that there is no way to retrieve files deleted using the shell,
 <code>rm -r</code> <em>should be used with great caution</em> (you might
@@ -2464,16 +2464,16 @@ <h3 class="callout-title">Copy with Multiple Filenames<a class="anchor" aria-lab
 <div class="codewrapper sourceCode" id="cb49">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir backup</span>
-<span id="cb49-2"><a href="#cb49-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp creatures/minotaur.dat creatures/unicorn.dat backup/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb49-1"><a href="#cb49-1" tabindex="-1"></a><span class="ex">$</span> mkdir backup</span>
+<span id="cb49-2"><a href="#cb49-2" tabindex="-1"></a><span class="ex">$</span> cp creatures/minotaur.dat creatures/unicorn.dat backup/</span></code></pre>
 </div>
 <p>In the example below, what does <code>cp</code> do when given three
 or more file names?</p>
 <div class="codewrapper sourceCode" id="cb50">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd creatures</span>
-<span id="cb50-2"><a href="#cb50-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" tabindex="-1"></a><span class="ex">$</span> cd creatures</span>
+<span id="cb50-2"><a href="#cb50-2" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2483,7 +2483,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb52">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp minotaur.dat unicorn.dat basilisk.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb52-1"><a href="#cb52-1" tabindex="-1"></a><span class="ex">$</span> cp minotaur.dat unicorn.dat basilisk.dat</span></code></pre>
 </div>
 </div>
 </div>
@@ -2513,12 +2513,12 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="section level3">
 <h3 id="using-wildcards-for-accessing-multiple-files-at-once">Using wildcards for accessing multiple files at once<a class="anchor" aria-label="anchor" href="#using-wildcards-for-accessing-multiple-files-at-once"></a>
 </h3>
-<div id="wildcards" class="callout callout">
+<div id="callout7" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="wildcards" class="callout-inner">
-<h3 class="callout-title">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="wildcards">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a>
 </h3>
 <div class="callout-content">
 <p><code>*</code> is a <strong>wildcard</strong>, which represents zero
@@ -2612,25 +2612,25 @@ <h3 class="callout-title">More on Wildcards<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb54">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb54-1"><a href="#cb54-1" aria-hidden="true" tabindex="-1"></a><span class="bu">.</span></span>
-<span id="cb54-2"><a href="#cb54-2" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
-<span id="cb54-3"><a href="#cb54-3" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
-<span id="cb54-4"><a href="#cb54-4" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
-<span id="cb54-5"><a href="#cb54-5" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
-<span id="cb54-6"><a href="#cb54-6" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
-<span id="cb54-7"><a href="#cb54-7" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
-<span id="cb54-8"><a href="#cb54-8" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
-<span id="cb54-9"><a href="#cb54-9" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
-<span id="cb54-10"><a href="#cb54-10" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
-<span id="cb54-11"><a href="#cb54-11" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
-<span id="cb54-12"><a href="#cb54-12" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
-<span id="cb54-13"><a href="#cb54-13" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
-<span id="cb54-14"><a href="#cb54-14" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> backup</span>
-<span id="cb54-15"><a href="#cb54-15" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
-<span id="cb54-16"><a href="#cb54-16" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
-<span id="cb54-17"><a href="#cb54-17" aria-hidden="true" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
-<span id="cb54-18"><a href="#cb54-18" aria-hidden="true" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
-<span id="cb54-19"><a href="#cb54-19" aria-hidden="true" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb54-1"><a href="#cb54-1" tabindex="-1"></a><span class="bu">.</span></span>
+<span id="cb54-2"><a href="#cb54-2" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
+<span id="cb54-3"><a href="#cb54-3" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
+<span id="cb54-4"><a href="#cb54-4" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
+<span id="cb54-5"><a href="#cb54-5" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
+<span id="cb54-6"><a href="#cb54-6" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
+<span id="cb54-7"><a href="#cb54-7" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
+<span id="cb54-8"><a href="#cb54-8" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
+<span id="cb54-9"><a href="#cb54-9" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
+<span id="cb54-10"><a href="#cb54-10" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
+<span id="cb54-11"><a href="#cb54-11" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
+<span id="cb54-12"><a href="#cb54-12" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
+<span id="cb54-13"><a href="#cb54-13" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
+<span id="cb54-14"><a href="#cb54-14" tabindex="-1"></a><span class="ex">├──</span> backup</span>
+<span id="cb54-15"><a href="#cb54-15" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
+<span id="cb54-16"><a href="#cb54-16" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
+<span id="cb54-17"><a href="#cb54-17" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
+<span id="cb54-18"><a href="#cb54-18" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
+<span id="cb54-19"><a href="#cb54-19" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span></code></pre>
 </div>
 <p>Before heading off to another field trip, she wants to back up her
 data and send some datasets to her colleague Bob. Sam uses the following
@@ -2638,57 +2638,57 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb55">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb55-1"><a href="#cb55-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>dataset<span class="pp">*</span> backup/datasets</span>
-<span id="cb55-2"><a href="#cb55-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp ____calibration____ backup/calibration</span>
-<span id="cb55-3"><a href="#cb55-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp 2015-____-____ send_to_bob/all_november_files/</span>
-<span id="cb55-4"><a href="#cb55-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp ____ send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb55-1"><a href="#cb55-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>dataset<span class="pp">*</span> backup/datasets</span>
+<span id="cb55-2"><a href="#cb55-2" tabindex="-1"></a><span class="ex">$</span> cp ____calibration____ backup/calibration</span>
+<span id="cb55-3"><a href="#cb55-3" tabindex="-1"></a><span class="ex">$</span> cp 2015-____-____ send_to_bob/all_november_files/</span>
+<span id="cb55-4"><a href="#cb55-4" tabindex="-1"></a><span class="ex">$</span> cp ____ send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
 </div>
 <p>Help Sam by filling in the blanks.</p>
 <p>The resulting directory structure should look like this</p>
 <div class="codewrapper sourceCode" id="cb56">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb56-1"><a href="#cb56-1" aria-hidden="true" tabindex="-1"></a><span class="bu">.</span></span>
-<span id="cb56-2"><a href="#cb56-2" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
-<span id="cb56-3"><a href="#cb56-3" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
-<span id="cb56-4"><a href="#cb56-4" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
-<span id="cb56-5"><a href="#cb56-5" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
-<span id="cb56-6"><a href="#cb56-6" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
-<span id="cb56-7"><a href="#cb56-7" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
-<span id="cb56-8"><a href="#cb56-8" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
-<span id="cb56-9"><a href="#cb56-9" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
-<span id="cb56-10"><a href="#cb56-10" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
-<span id="cb56-11"><a href="#cb56-11" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
-<span id="cb56-12"><a href="#cb56-12" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
-<span id="cb56-13"><a href="#cb56-13" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
-<span id="cb56-14"><a href="#cb56-14" aria-hidden="true" tabindex="-1"></a><span class="ex">├──</span> backup</span>
-<span id="cb56-15"><a href="#cb56-15" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
-<span id="cb56-16"><a href="#cb56-16" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-23-calibration.txt</span>
-<span id="cb56-17"><a href="#cb56-17" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-26-calibration.txt</span>
-<span id="cb56-18"><a href="#cb56-18" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> │   └── 2015-11-23-calibration.txt</span>
-<span id="cb56-19"><a href="#cb56-19" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
-<span id="cb56-20"><a href="#cb56-20" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset1.txt</span>
-<span id="cb56-21"><a href="#cb56-21" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset2.txt</span>
-<span id="cb56-22"><a href="#cb56-22" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset_overview.txt</span>
-<span id="cb56-23"><a href="#cb56-23" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset1.txt</span>
-<span id="cb56-24"><a href="#cb56-24" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset2.txt</span>
-<span id="cb56-25"><a href="#cb56-25" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset_overview.txt</span>
-<span id="cb56-26"><a href="#cb56-26" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset1.txt</span>
-<span id="cb56-27"><a href="#cb56-27" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset2.txt</span>
-<span id="cb56-28"><a href="#cb56-28" aria-hidden="true" tabindex="-1"></a><span class="ex">│  </span>     └── 2015-11-23-dataset_overview.txt</span>
-<span id="cb56-29"><a href="#cb56-29" aria-hidden="true" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
-<span id="cb56-30"><a href="#cb56-30" aria-hidden="true" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
-<span id="cb56-31"><a href="#cb56-31" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset1.txt</span>
-<span id="cb56-32"><a href="#cb56-32" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset2.txt</span>
-<span id="cb56-33"><a href="#cb56-33" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset_overview.txt</span>
-<span id="cb56-34"><a href="#cb56-34" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset1.txt</span>
-<span id="cb56-35"><a href="#cb56-35" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset2.txt</span>
-<span id="cb56-36"><a href="#cb56-36" aria-hidden="true" tabindex="-1"></a>    <span class="ex">│  </span> └── 2015-11-23-dataset_overview.txt</span>
-<span id="cb56-37"><a href="#cb56-37" aria-hidden="true" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span>
-<span id="cb56-38"><a href="#cb56-38" aria-hidden="true" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-calibration.txt</span>
-<span id="cb56-39"><a href="#cb56-39" aria-hidden="true" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
-<span id="cb56-40"><a href="#cb56-40" aria-hidden="true" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
-<span id="cb56-41"><a href="#cb56-41" aria-hidden="true" tabindex="-1"></a>        <span class="ex">└──</span> 2015-11-23-dataset_overview.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb56-1"><a href="#cb56-1" tabindex="-1"></a><span class="bu">.</span></span>
+<span id="cb56-2"><a href="#cb56-2" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-calibration.txt</span>
+<span id="cb56-3"><a href="#cb56-3" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset1.txt</span>
+<span id="cb56-4"><a href="#cb56-4" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset2.txt</span>
+<span id="cb56-5"><a href="#cb56-5" tabindex="-1"></a><span class="ex">├──</span> 2015-10-23-dataset_overview.txt</span>
+<span id="cb56-6"><a href="#cb56-6" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-calibration.txt</span>
+<span id="cb56-7"><a href="#cb56-7" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset1.txt</span>
+<span id="cb56-8"><a href="#cb56-8" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset2.txt</span>
+<span id="cb56-9"><a href="#cb56-9" tabindex="-1"></a><span class="ex">├──</span> 2015-10-26-dataset_overview.txt</span>
+<span id="cb56-10"><a href="#cb56-10" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-calibration.txt</span>
+<span id="cb56-11"><a href="#cb56-11" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
+<span id="cb56-12"><a href="#cb56-12" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
+<span id="cb56-13"><a href="#cb56-13" tabindex="-1"></a><span class="ex">├──</span> 2015-11-23-dataset_overview.txt</span>
+<span id="cb56-14"><a href="#cb56-14" tabindex="-1"></a><span class="ex">├──</span> backup</span>
+<span id="cb56-15"><a href="#cb56-15" tabindex="-1"></a><span class="ex">│  </span> ├── calibration</span>
+<span id="cb56-16"><a href="#cb56-16" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-23-calibration.txt</span>
+<span id="cb56-17"><a href="#cb56-17" tabindex="-1"></a><span class="ex">│  </span> │   ├── 2015-10-26-calibration.txt</span>
+<span id="cb56-18"><a href="#cb56-18" tabindex="-1"></a><span class="ex">│  </span> │   └── 2015-11-23-calibration.txt</span>
+<span id="cb56-19"><a href="#cb56-19" tabindex="-1"></a><span class="ex">│  </span> └── datasets</span>
+<span id="cb56-20"><a href="#cb56-20" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset1.txt</span>
+<span id="cb56-21"><a href="#cb56-21" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset2.txt</span>
+<span id="cb56-22"><a href="#cb56-22" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-23-dataset_overview.txt</span>
+<span id="cb56-23"><a href="#cb56-23" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset1.txt</span>
+<span id="cb56-24"><a href="#cb56-24" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset2.txt</span>
+<span id="cb56-25"><a href="#cb56-25" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-10-26-dataset_overview.txt</span>
+<span id="cb56-26"><a href="#cb56-26" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset1.txt</span>
+<span id="cb56-27"><a href="#cb56-27" tabindex="-1"></a><span class="ex">│  </span>     ├── 2015-11-23-dataset2.txt</span>
+<span id="cb56-28"><a href="#cb56-28" tabindex="-1"></a><span class="ex">│  </span>     └── 2015-11-23-dataset_overview.txt</span>
+<span id="cb56-29"><a href="#cb56-29" tabindex="-1"></a><span class="ex">└──</span> send_to_bob</span>
+<span id="cb56-30"><a href="#cb56-30" tabindex="-1"></a>    <span class="ex">├──</span> all_datasets_created_on_a_23rd</span>
+<span id="cb56-31"><a href="#cb56-31" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset1.txt</span>
+<span id="cb56-32"><a href="#cb56-32" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset2.txt</span>
+<span id="cb56-33"><a href="#cb56-33" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-10-23-dataset_overview.txt</span>
+<span id="cb56-34"><a href="#cb56-34" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset1.txt</span>
+<span id="cb56-35"><a href="#cb56-35" tabindex="-1"></a>    <span class="ex">│  </span> ├── 2015-11-23-dataset2.txt</span>
+<span id="cb56-36"><a href="#cb56-36" tabindex="-1"></a>    <span class="ex">│  </span> └── 2015-11-23-dataset_overview.txt</span>
+<span id="cb56-37"><a href="#cb56-37" tabindex="-1"></a>    <span class="ex">└──</span> all_november_files</span>
+<span id="cb56-38"><a href="#cb56-38" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-calibration.txt</span>
+<span id="cb56-39"><a href="#cb56-39" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset1.txt</span>
+<span id="cb56-40"><a href="#cb56-40" tabindex="-1"></a>        <span class="ex">├──</span> 2015-11-23-dataset2.txt</span>
+<span id="cb56-41"><a href="#cb56-41" tabindex="-1"></a>        <span class="ex">└──</span> 2015-11-23-dataset_overview.txt</span></code></pre>
 </div>
 </div>
 </div>
@@ -2703,9 +2703,9 @@ <h4 class="accordion-header" id="headingSolution8">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb57">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb57-1"><a href="#cb57-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>calibration.txt backup/calibration</span>
-<span id="cb57-2"><a href="#cb57-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp 2015-11-<span class="pp">*</span> send_to_bob/all_november_files/</span>
-<span id="cb57-3"><a href="#cb57-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>-23-dataset<span class="pp">*</span> send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb57-1"><a href="#cb57-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>calibration.txt backup/calibration</span>
+<span id="cb57-2"><a href="#cb57-2" tabindex="-1"></a><span class="ex">$</span> cp 2015-11-<span class="pp">*</span> send_to_bob/all_november_files/</span>
+<span id="cb57-3"><a href="#cb57-3" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>-23-dataset<span class="pp">*</span> send_to_bob/all_datasets_created_on_a_23rd/</span></code></pre>
 </div>
 </div>
 </div>
@@ -2724,7 +2724,7 @@ <h3 class="callout-title">Organizing Directories and Files<a class="anchor" aria
 <div class="codewrapper sourceCode" id="cb58">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb58-1"><a href="#cb58-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb58-1"><a href="#cb58-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2738,7 +2738,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb60">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb60-1"><a href="#cb60-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb60-1"><a href="#cb60-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-F</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2748,7 +2748,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb62">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb62-1"><a href="#cb62-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls analyzed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb62-1"><a href="#cb62-1" tabindex="-1"></a><span class="ex">$</span> ls analyzed</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2768,7 +2768,7 @@ <h4 class="accordion-header" id="headingSolution9">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb64">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb64-1"><a href="#cb64-1" aria-hidden="true" tabindex="-1"></a><span class="fu">mv</span> <span class="pp">*</span>.dat analyzed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb64-1"><a href="#cb64-1" tabindex="-1"></a><span class="fu">mv</span> <span class="pp">*</span>.dat analyzed</span></code></pre>
 </div>
 <p>Jamie needs to move her files <code>fructose.dat</code> and
 <code>sucrose.dat</code> to the <code>analyzed</code> directory. The
@@ -2810,39 +2810,39 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb66">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb66-1"><a href="#cb66-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
-<span id="cb66-2"><a href="#cb66-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data</span>
-<span id="cb66-3"><a href="#cb66-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span>
-<span id="cb66-4"><a href="#cb66-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb66-1"><a href="#cb66-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
+<span id="cb66-2"><a href="#cb66-2" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data</span>
+<span id="cb66-3"><a href="#cb66-3" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span>
+<span id="cb66-4"><a href="#cb66-4" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb67">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb67-1"><a href="#cb67-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
-<span id="cb67-2"><a href="#cb67-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
-<span id="cb67-3"><a href="#cb67-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
-<span id="cb67-4"><a href="#cb67-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd data</span>
-<span id="cb67-5"><a href="#cb67-5" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb67-1"><a href="#cb67-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
+<span id="cb67-2"><a href="#cb67-2" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
+<span id="cb67-3"><a href="#cb67-3" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
+<span id="cb67-4"><a href="#cb67-4" tabindex="-1"></a><span class="ex">$</span> cd data</span>
+<span id="cb67-5"><a href="#cb67-5" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb68">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb68-1"><a href="#cb68-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span>
-<span id="cb68-2"><a href="#cb68-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb68-1"><a href="#cb68-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/raw</span>
+<span id="cb68-2"><a href="#cb68-2" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20/data/processed</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb69">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb69-1"><a href="#cb69-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/raw</span>
-<span id="cb69-2"><a href="#cb69-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb69-1"><a href="#cb69-1" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/raw</span>
+<span id="cb69-2"><a href="#cb69-2" tabindex="-1"></a><span class="ex">$</span> mkdir <span class="at">-p</span> 2016-05-20/data/processed</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb70">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb70-1"><a href="#cb70-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
-<span id="cb70-2"><a href="#cb70-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
-<span id="cb70-3"><a href="#cb70-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
-<span id="cb70-4"><a href="#cb70-4" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb70-1"><a href="#cb70-1" tabindex="-1"></a><span class="ex">$</span> mkdir 2016-05-20</span>
+<span id="cb70-2"><a href="#cb70-2" tabindex="-1"></a><span class="ex">$</span> cd 2016-05-20</span>
+<span id="cb70-3"><a href="#cb70-3" tabindex="-1"></a><span class="ex">$</span> mkdir data</span>
+<span id="cb70-4"><a href="#cb70-4" tabindex="-1"></a><span class="ex">$</span> mkdir raw processed</span></code></pre>
 </div>
 </div>
 </div>
@@ -2960,7 +2960,7 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2972,7 +2972,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc cubane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> wc cubane.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2989,7 +2989,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="pp">*</span>.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="pp">*</span>.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3009,7 +3009,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3025,12 +3025,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <p>The <code>-m</code> and <code>-w</code> options can also be used with
 the <code>wc</code> command to show only the number of characters or the
 number of words, respectively.</p>
-<div id="why-isnt-it-doing-anything" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="why-isnt-it-doing-anything" class="callout-inner">
-<h3 class="callout-title">Why Isn’t It Doing Anything?<a class="anchor" aria-label="anchor" href="#why-isnt-it-doing-anything"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="why-isnt-it-doing-anything">Why Isn’t It Doing Anything?<a class="anchor" aria-label="anchor" href="#why-isnt-it-doing-anything"></a>
 </h3>
 <div class="callout-content">
 <p>What happens if a command is supposed to process a file, but we don’t
@@ -3038,7 +3038,7 @@ <h3 class="callout-title">Why Isn’t It Doing Anything?<a class="anchor" aria-l
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span></span></code></pre>
 </div>
 <p>but don’t type <code>*.pdb</code> (or anything else) after the
 command? Since it doesn’t have any filenames, <code>wc</code> assumes it
@@ -3062,7 +3062,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="op">&gt;</span> lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="op">&gt;</span> lengths.txt</span></code></pre>
 </div>
 <p>The greater than symbol, <code>&gt;</code>, tells the shell to
 <strong>redirect</strong> the command’s output to a file instead of
@@ -3076,7 +3076,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> ls lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3091,7 +3091,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cat lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> cat lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3104,12 +3104,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
   15  propane.pdb
  107  total</code></pre>
 </div>
-<div id="output-page-by-page" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="output-page-by-page" class="callout-inner">
-<h3 class="callout-title">Output Page by Page<a class="anchor" aria-label="anchor" href="#output-page-by-page"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="output-page-by-page">Output Page by Page<a class="anchor" aria-label="anchor" href="#output-page-by-page"></a>
 </h3>
 <div class="callout-content">
 <p>We’ll continue to use <code>cat</code> in this lesson, for
@@ -3187,7 +3187,7 @@ <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3210,8 +3210,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> sorted-lengths.txt</span>
-<span id="cb20-2"><a href="#cb20-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 sorted-lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> sorted-lengths.txt</span>
+<span id="cb20-2"><a href="#cb20-2" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 sorted-lengths.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3223,12 +3223,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 20, and so on. Since <code>sorted-lengths.txt</code> contains the
 lengths of our files ordered from least to greatest, the output of
 <code>head</code> must be the file with the fewest lines.</p>
-<div id="redirecting-to-the-same-file" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="redirecting-to-the-same-file" class="callout-inner">
-<h3 class="callout-title">Redirecting to the same file<a class="anchor" aria-label="anchor" href="#redirecting-to-the-same-file"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="redirecting-to-the-same-file">Redirecting to the same file<a class="anchor" aria-label="anchor" href="#redirecting-to-the-same-file"></a>
 </h3>
 <div class="callout-content">
 <p>It’s a very bad idea to try redirecting the output of a command that
@@ -3236,7 +3236,7 @@ <h3 class="callout-title">Redirecting to the same file<a class="anchor" aria-lab
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> lengths.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="op">&gt;</span> lengths.txt</span></code></pre>
 </div>
 <p>Doing something like this may give you incorrect results and/or
 delete the contents of <code>lengths.txt</code>.</p>
@@ -3259,7 +3259,7 @@ <h3 class="callout-title">What Does<code>&gt;&gt;</code>Mean?<a class="anchor" a
 <div class="codewrapper sourceCode" id="cb23">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo The echo command prints text</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" tabindex="-1"></a><span class="ex">$</span> echo The echo command prints text</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3271,13 +3271,13 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;</span> testfile01.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;</span> testfile01.txt</span></code></pre>
 </div>
 <p>and:</p>
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;&gt;</span> testfile02.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> echo hello <span class="op">&gt;&gt;</span> testfile02.txt</span></code></pre>
 </div>
 <p>Hint: Try executing each command twice in a row and then examining
 the output files.</p>
@@ -3320,8 +3320,8 @@ <h3 class="callout-title">Appending Data<a class="anchor" aria-label="anchor" hr
 <div class="codewrapper sourceCode" id="cb27">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 3 animals.csv <span class="op">&gt;</span> animals-subset.csv</span>
-<span id="cb27-2"><a href="#cb27-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 2 animals.csv <span class="op">&gt;&gt;</span> animals-subset.csv</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 3 animals.csv <span class="op">&gt;</span> animals-subset.csv</span>
+<span id="cb27-2"><a href="#cb27-2" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 2 animals.csv <span class="op">&gt;&gt;</span> animals-subset.csv</span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li>The first three lines of <code>animals.csv</code>
@@ -3368,7 +3368,7 @@ <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> sort <span class="at">-n</span> lengths.txt <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3393,7 +3393,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3411,7 +3411,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3502,7 +3502,7 @@ <h3 class="callout-title">Pipe Reading Comprehension<a class="anchor" aria-label
 <div class="codewrapper sourceCode" id="cb35">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cat animals.csv <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5 <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 3 <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-r</span> <span class="op">&gt;</span> final.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" tabindex="-1"></a><span class="ex">$</span> cat animals.csv <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5 <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 3 <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-r</span> <span class="op">&gt;</span> final.txt</span></code></pre>
 </div>
 <p>Hint: build the pipeline up one command at a time to test your
 understanding</p>
@@ -3544,7 +3544,7 @@ <h3 class="callout-title">Pipe Construction<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv</span></code></pre>
 </div>
 <p>The <code>cut</code> command is used to remove or ‘cut out’ certain
 sections of each line in the file, and <code>cut</code> expects the
@@ -3583,7 +3583,7 @@ <h4 class="accordion-header" id="headingSolution6">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> cut <span class="at">-d</span> , <span class="at">-f</span> 2 animals.csv <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span></code></pre>
 </div>
 </div>
 </div>
@@ -3650,8 +3650,8 @@ <h4 class="accordion-header" id="headingSolution7">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd north-pacific-gyre</span>
-<span id="cb41-2"><a href="#cb41-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="ex">$</span> cd north-pacific-gyre</span>
+<span id="cb41-2"><a href="#cb41-2" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt</span></code></pre>
 </div>
 <p>The output is 18 lines that look like this:</p>
 <div class="codewrapper">
@@ -3669,7 +3669,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3688,7 +3688,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.txt <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3706,7 +3706,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> ls <span class="pp">*</span>Z.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="pp">*</span>Z.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3860,7 +3860,7 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 5 basilisk.dat minotaur.dat unicorn.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 5 basilisk.dat minotaur.dat unicorn.dat</span></code></pre>
 </div>
 <p>We would like to print out the classification for each species, which
 is given on the second line of each file. For each file, we would need
@@ -3871,24 +3871,24 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb2">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="co"># The word "for" indicates the start of a "For-loop" command</span></span>
-<span id="cb2-2"><a href="#cb2-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> thing <span class="kw">in</span> list_of_things </span>
-<span id="cb2-3"><a href="#cb2-3" aria-hidden="true" tabindex="-1"></a><span class="co">#The word "do" indicates the start of job execution list</span></span>
-<span id="cb2-4"><a href="#cb2-4" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span> </span>
-<span id="cb2-5"><a href="#cb2-5" aria-hidden="true" tabindex="-1"></a>    <span class="co"># Indentation within the loop is not required, but aids legibility</span></span>
-<span id="cb2-6"><a href="#cb2-6" aria-hidden="true" tabindex="-1"></a>    <span class="ex">operation_using/command</span> <span class="va">$thing</span> </span>
-<span id="cb2-7"><a href="#cb2-7" aria-hidden="true" tabindex="-1"></a><span class="co"># The word "done" indicates the end of a loop</span></span>
-<span id="cb2-8"><a href="#cb2-8" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span>  </span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" tabindex="-1"></a><span class="co"># The word "for" indicates the start of a "For-loop" command</span></span>
+<span id="cb2-2"><a href="#cb2-2" tabindex="-1"></a><span class="cf">for</span> thing <span class="kw">in</span> list_of_things </span>
+<span id="cb2-3"><a href="#cb2-3" tabindex="-1"></a><span class="co">#The word "do" indicates the start of job execution list</span></span>
+<span id="cb2-4"><a href="#cb2-4" tabindex="-1"></a><span class="cf">do</span> </span>
+<span id="cb2-5"><a href="#cb2-5" tabindex="-1"></a>    <span class="co"># Indentation within the loop is not required, but aids legibility</span></span>
+<span id="cb2-6"><a href="#cb2-6" tabindex="-1"></a>    <span class="ex">operation_using/command</span> <span class="va">$thing</span> </span>
+<span id="cb2-7"><a href="#cb2-7" tabindex="-1"></a><span class="co"># The word "done" indicates the end of a loop</span></span>
+<span id="cb2-8"><a href="#cb2-8" tabindex="-1"></a><span class="cf">done</span>  </span></code></pre>
 </div>
 <p>and we can apply this to our example like this:</p>
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in basilisk.dat minotaur.dat unicorn.dat</span>
-<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb3-3"><a href="#cb3-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
-<span id="cb3-4"><a href="#cb3-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
-<span id="cb3-5"><a href="#cb3-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> for filename in basilisk.dat minotaur.dat unicorn.dat</span>
+<span id="cb3-2"><a href="#cb3-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb3-3"><a href="#cb3-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
+<span id="cb3-4"><a href="#cb3-4" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
+<span id="cb3-5"><a href="#cb3-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3900,12 +3900,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 unicorn.dat
 CLASSIFICATION: equus monoceros</code></pre>
 </div>
-<div id="follow-the-prompt" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="follow-the-prompt" class="callout-inner">
-<h3 class="callout-title">Follow the Prompt<a class="anchor" aria-label="anchor" href="#follow-the-prompt"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="follow-the-prompt">Follow the Prompt<a class="anchor" aria-label="anchor" href="#follow-the-prompt"></a>
 </h3>
 <div class="callout-content">
 <p>The shell prompt changes from <code>$</code> to <code>&gt;</code> and
@@ -3946,12 +3946,12 @@ <h3 class="callout-title">Follow the Prompt<a class="anchor" aria-label="anchor"
 runs the <code>head</code> command on that file, and <code>tail</code>
 on the output of that. Since the list was only three items, the shell
 exits the <code>for</code> loop.</p>
-<div id="same-symbols-different-meanings" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="same-symbols-different-meanings" class="callout-inner">
-<h3 class="callout-title">Same Symbols, Different Meanings<a class="anchor" aria-label="anchor" href="#same-symbols-different-meanings"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="same-symbols-different-meanings">Same Symbols, Different Meanings<a class="anchor" aria-label="anchor" href="#same-symbols-different-meanings"></a>
 </h3>
 <div class="callout-content">
 <p>Here we see <code>&gt;</code> being used as a shell prompt, whereas
@@ -3977,19 +3977,19 @@ <h3 class="callout-title">Same Symbols, Different Meanings<a class="anchor" aria
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for x in basilisk.dat minotaur.dat unicorn.dat</span>
-<span id="cb5-2"><a href="#cb5-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb5-3"><a href="#cb5-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$x</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
-<span id="cb5-4"><a href="#cb5-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> for x in basilisk.dat minotaur.dat unicorn.dat</span>
+<span id="cb5-2"><a href="#cb5-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb5-3"><a href="#cb5-3" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$x</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
+<span id="cb5-4"><a href="#cb5-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>or:</p>
 <div class="codewrapper sourceCode" id="cb6">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for temperature in basilisk.dat minotaur.dat unicorn.dat</span>
-<span id="cb6-2"><a href="#cb6-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb6-3"><a href="#cb6-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$temperature</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
-<span id="cb6-4"><a href="#cb6-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb6-1"><a href="#cb6-1" tabindex="-1"></a><span class="ex">$</span> for temperature in basilisk.dat minotaur.dat unicorn.dat</span>
+<span id="cb6-2"><a href="#cb6-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb6-3"><a href="#cb6-3" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 2 <span class="va">$temperature</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 1</span>
+<span id="cb6-4"><a href="#cb6-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>it would work exactly the same way. <em>Don’t do this.</em> Programs
 are only useful if people can understand them, so meaningless names
@@ -4020,15 +4020,15 @@ <h3 class="callout-title">Write your own loop<a class="anchor" aria-label="ancho
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for loop_variable in 0 1 2 3 4 5 6 7 8 9</span>
-<span id="cb7-2"><a href="#cb7-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb7-3"><a href="#cb7-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$loop_variable</span></span>
-<span id="cb7-4"><a href="#cb7-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> for loop_variable in 0 1 2 3 4 5 6 7 8 9</span>
+<span id="cb7-2"><a href="#cb7-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb7-3"><a href="#cb7-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$loop_variable</span></span>
+<span id="cb7-4"><a href="#cb7-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4068,19 +4068,19 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb10">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb10-2"><a href="#cb10-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb10-3"><a href="#cb10-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">*.pdb</span></span>
-<span id="cb10-4"><a href="#cb10-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb10-2"><a href="#cb10-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb10-3"><a href="#cb10-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">*.pdb</span></span>
+<span id="cb10-4"><a href="#cb10-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>Now, what is the output of the following code?</p>
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb11-2"><a href="#cb11-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb11-3"><a href="#cb11-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$datafile</span></span>
-<span id="cb11-4"><a href="#cb11-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb11-2"><a href="#cb11-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb11-3"><a href="#cb11-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$datafile</span></span>
+<span id="cb11-4"><a href="#cb11-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>Why do these two loops give different outputs?</p>
 </div>
@@ -4091,7 +4091,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>The first code block gives the same output on each iteration through
 the loop. Bash expands the wildcard <code>*.pdb</code> within the loop
@@ -4101,10 +4101,10 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb12">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in cubane.pdb  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
-<span id="cb12-2"><a href="#cb12-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb12-3"><a href="#cb12-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">cubane.pdb</span>  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
-<span id="cb12-4"><a href="#cb12-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb12-1"><a href="#cb12-1" tabindex="-1"></a><span class="ex">$</span> for datafile in cubane.pdb  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
+<span id="cb12-2"><a href="#cb12-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb12-3"><a href="#cb12-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="ex">cubane.pdb</span>  ethane.pdb  methane.pdb  octane.pdb  pentane.pdb  propane.pdb</span>
+<span id="cb12-4"><a href="#cb12-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4146,10 +4146,10 @@ <h3 class="callout-title">Limiting Sets of Files<a class="anchor" aria-label="an
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in c<span class="pp">*</span></span>
-<span id="cb15-2"><a href="#cb15-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb15-3"><a href="#cb15-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
-<span id="cb15-4"><a href="#cb15-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> for filename in c<span class="pp">*</span></span>
+<span id="cb15-2"><a href="#cb15-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb15-3"><a href="#cb15-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
+<span id="cb15-4"><a href="#cb15-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li>No files are listed.</li>
@@ -4166,7 +4166,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so any file name starting with the letter c, followed by
@@ -4187,10 +4187,10 @@ <h3 class="callout-title">Limiting Sets of Files<em>(continued)</em><a class="an
 <div class="codewrapper sourceCode" id="cb16">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>c<span class="pp">*</span></span>
-<span id="cb16-2"><a href="#cb16-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb16-3"><a href="#cb16-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
-<span id="cb16-4"><a href="#cb16-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb16-1"><a href="#cb16-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>c<span class="pp">*</span></span>
+<span id="cb16-2"><a href="#cb16-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb16-3"><a href="#cb16-3" tabindex="-1"></a><span class="op">&gt;</span>     ls <span class="va">$filename</span></span>
+<span id="cb16-4"><a href="#cb16-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li>The same files would be listed.</li>
@@ -4208,7 +4208,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so a file name with zero or more characters before a letter
@@ -4230,11 +4230,11 @@ <h3 class="callout-title">Saving to a File in a Loop - Part One<a class="anchor"
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> alkanes <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
-<span id="cb17-2"><a href="#cb17-2" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb17-3"><a href="#cb17-3" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$alkanes</span></span>
-<span id="cb17-4"><a href="#cb17-4" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$alkanes</span> <span class="op">&gt;</span> alkanes.pdb</span>
-<span id="cb17-5"><a href="#cb17-5" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="cf">for</span> alkanes <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
+<span id="cb17-2"><a href="#cb17-2" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb17-3"><a href="#cb17-3" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$alkanes</span></span>
+<span id="cb17-4"><a href="#cb17-4" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$alkanes</span> <span class="op">&gt;</span> alkanes.pdb</span>
+<span id="cb17-5"><a href="#cb17-5" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li>Prints <code>cubane.pdb</code>, <code>ethane.pdb</code>,
@@ -4259,7 +4259,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5">Show me the solution</h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>The text from each file in turn gets written to the
@@ -4284,10 +4284,10 @@ <h3 class="callout-title">Saving to a File in a Loop - Part Two<a class="anchor"
 <div class="codewrapper sourceCode" id="cb18">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
-<span id="cb18-2"><a href="#cb18-2" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb18-3"><a href="#cb18-3" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
-<span id="cb18-4"><a href="#cb18-4" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="pp">*</span>.pdb</span>
+<span id="cb18-2"><a href="#cb18-2" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb18-3"><a href="#cb18-3" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
+<span id="cb18-4"><a href="#cb18-4" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <ol style="list-style-type: decimal">
 <li>All of the text from <code>cubane.pdb</code>,
@@ -4315,7 +4315,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution6" aria-expanded="false" aria-controls="collapseSolution6">
   <h4 class="accordion-header" id="headingSolution6">Show me the solution</h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <p>3 is the correct answer. <code>&gt;&gt;</code> appends to a file,
 rather than overwriting it with the redirected output from a command.
@@ -4331,11 +4331,11 @@ <h4 class="accordion-header" id="headingSolution6">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
-<span id="cb19-2"><a href="#cb19-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb19-3"><a href="#cb19-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
-<span id="cb19-4"><a href="#cb19-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
-<span id="cb19-5"><a href="#cb19-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
+<span id="cb19-2"><a href="#cb19-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb19-3"><a href="#cb19-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$filename</span></span>
+<span id="cb19-4"><a href="#cb19-4" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
+<span id="cb19-5"><a href="#cb19-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>The shell starts by expanding <code>*.dat</code> to create the list
 of files it will process. The <strong>loop body</strong> then executes
@@ -4345,7 +4345,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> echo hello there</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> echo hello there</span></code></pre>
 </div>
 <p>prints:</p>
 <div class="codewrapper">
@@ -4359,11 +4359,11 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
-<span id="cb22-2"><a href="#cb22-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb22-3"><a href="#cb22-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     <span class="va">$filename</span></span>
-<span id="cb22-4"><a href="#cb22-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
-<span id="cb22-5"><a href="#cb22-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
+<span id="cb22-2"><a href="#cb22-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb22-3"><a href="#cb22-3" tabindex="-1"></a><span class="op">&gt;</span>     <span class="va">$filename</span></span>
+<span id="cb22-4"><a href="#cb22-4" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="va">$filename</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
+<span id="cb22-5"><a href="#cb22-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>because then the first time through the loop, when
 <code>$filename</code> expanded to <code>basilisk.dat</code>, the shell
@@ -4371,12 +4371,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <code>head</code> and <code>tail</code> combination selects lines 81-100
 from whatever file is being processed (assuming the file has at least
 100 lines).</p>
-<div id="spaces-in-names" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="spaces-in-names" class="callout-inner">
-<h3 class="callout-title">Spaces in Names<a class="anchor" aria-label="anchor" href="#spaces-in-names"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="spaces-in-names">Spaces in Names<a class="anchor" aria-label="anchor" href="#spaces-in-names"></a>
 </h3>
 <div class="callout-content">
 <p>Spaces are used to separate the elements of the list that we are
@@ -4390,10 +4390,10 @@ <h3 class="callout-title">Spaces in Names<a class="anchor" aria-label="anchor" h
 <div class="codewrapper sourceCode" id="cb24">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="st">"red dragon.dat"</span> <span class="st">"purple unicorn.dat"</span></span>
-<span id="cb24-2"><a href="#cb24-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb24-3"><a href="#cb24-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="st">"</span><span class="va">$filename</span><span class="st">"</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
-<span id="cb24-4"><a href="#cb24-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="st">"red dragon.dat"</span> <span class="st">"purple unicorn.dat"</span></span>
+<span id="cb24-2"><a href="#cb24-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb24-3"><a href="#cb24-3" tabindex="-1"></a><span class="op">&gt;</span>     head <span class="ex">-n</span> 100 <span class="st">"</span><span class="va">$filename</span><span class="st">"</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 20</span>
+<span id="cb24-4"><a href="#cb24-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>It is simpler to avoid using spaces (or other special characters) in
 filenames.</p>
@@ -4433,13 +4433,13 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb27">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>.dat original-<span class="pp">*</span>.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" tabindex="-1"></a><span class="ex">$</span> cp <span class="pp">*</span>.dat original-<span class="pp">*</span>.dat</span></code></pre>
 </div>
 <p>because that would expand to:</p>
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cp basilisk.dat minotaur.dat unicorn.dat original-<span class="pp">*</span>.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> cp basilisk.dat minotaur.dat unicorn.dat original-<span class="pp">*</span>.dat</span></code></pre>
 </div>
 <p>This wouldn’t back up our files, instead we get an error:</p>
 <div class="codewrapper">
@@ -4456,10 +4456,10 @@ <h3 class="code-label">ERROR<i aria-hidden="true" data-feather="chevron-left"></
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
-<span id="cb30-2"><a href="#cb30-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb30-3"><a href="#cb30-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     cp <span class="va">$filename</span> original-<span class="va">$filename</span></span>
-<span id="cb30-4"><a href="#cb30-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> for filename in <span class="pp">*</span>.dat</span>
+<span id="cb30-2"><a href="#cb30-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb30-3"><a href="#cb30-3" tabindex="-1"></a><span class="op">&gt;</span>     cp <span class="va">$filename</span> original-<span class="va">$filename</span></span>
+<span id="cb30-4"><a href="#cb30-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>This loop runs the <code>cp</code> command once for each filename.
 The first time, when <code>$filename</code> expands to
@@ -4467,19 +4467,19 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cp</span> basilisk.dat original-basilisk.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="fu">cp</span> basilisk.dat original-basilisk.dat</span></code></pre>
 </div>
 <p>The second time, the command is:</p>
 <div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cp</span> minotaur.dat original-minotaur.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="fu">cp</span> minotaur.dat original-minotaur.dat</span></code></pre>
 </div>
 <p>The third and last time, the command is:</p>
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cp</span> unicorn.dat original-unicorn.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="fu">cp</span> unicorn.dat original-unicorn.dat</span></code></pre>
 </div>
 <p>Since the <code>cp</code> command does not normally produce any
 output, it’s hard to check that the loop is working correctly. However,
@@ -4509,12 +4509,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd</span>
-<span id="cb34-2"><a href="#cb34-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/north-pacific-gyre</span>
-<span id="cb34-3"><a href="#cb34-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
-<span id="cb34-4"><a href="#cb34-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb34-5"><a href="#cb34-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span></span>
-<span id="cb34-6"><a href="#cb34-6" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> cd</span>
+<span id="cb34-2"><a href="#cb34-2" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/north-pacific-gyre</span>
+<span id="cb34-3"><a href="#cb34-3" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
+<span id="cb34-4"><a href="#cb34-4" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb34-5"><a href="#cb34-5" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span></span>
+<span id="cb34-6"><a href="#cb34-6" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4533,10 +4533,10 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
-<span id="cb36-2"><a href="#cb36-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb36-3"><a href="#cb36-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb36-4"><a href="#cb36-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
+<span id="cb36-2"><a href="#cb36-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb36-3"><a href="#cb36-3" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb36-4"><a href="#cb36-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4559,14 +4559,14 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
 </div>
 <p>Using the <kbd>←</kbd>, Nelle navigates to the <code>echo</code>
 command and changes it to <code>bash goostats.sh</code>:</p>
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
 </div>
 <p>When she presses <kbd>Enter</kbd>, the shell runs the modified
 command. However, nothing appears to happen — there is no output. After
@@ -4578,15 +4578,15 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb40">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span><span class="kw">;</span></span>
-<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a><span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" tabindex="-1"></a><span class="ex">$</span> for datafile in NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt<span class="kw">;</span> <span class="cf">do</span> <span class="bu">echo</span> <span class="va">$datafile</span><span class="kw">;</span></span>
+<span id="cb40-2"><a href="#cb40-2" tabindex="-1"></a><span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span><span class="kw">;</span> <span class="cf">done</span></span></code></pre>
 </div>
-<div id="beginning-and-end" class="callout callout">
+<div id="callout4" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="beginning-and-end" class="callout-inner">
-<h3 class="callout-title">Beginning and End<a class="anchor" aria-label="anchor" href="#beginning-and-end"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="beginning-and-end">Beginning and End<a class="anchor" aria-label="anchor" href="#beginning-and-end"></a>
 </h3>
 <div class="callout-content">
 <p>We can move to the beginning of a line in the shell by typing
@@ -4611,12 +4611,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <code>cat stats-NENE01729B.txt</code> to examine one of the output
 files. It looks good, so she decides to get some coffee and catch up on
 her reading.</p>
-<div id="those-who-know-history-can-choose-to-repeat-it" class="callout callout">
+<div id="callout5" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="those-who-know-history-can-choose-to-repeat-it" class="callout-inner">
-<h3 class="callout-title">Those Who Know History Can Choose to Repeat
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="those-who-know-history-can-choose-to-repeat-it">Those Who Know History Can Choose to Repeat
 It<a class="anchor" aria-label="anchor" href="#those-who-know-history-can-choose-to-repeat-it"></a>
 </h3>
 <div class="callout-content">
@@ -4628,7 +4628,7 @@ <h3 class="callout-title">Those Who Know History Can Choose to Repeat
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4645,12 +4645,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 </div>
 </div>
-<div id="other-history-commands" class="callout callout">
+<div id="callout6" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="other-history-commands" class="callout-inner">
-<h3 class="callout-title">Other History Commands<a class="anchor" aria-label="anchor" href="#other-history-commands"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="other-history-commands">Other History Commands<a class="anchor" aria-label="anchor" href="#other-history-commands"></a>
 </h3>
 <div class="callout-content">
 <p>There are a number of other shortcut commands for getting at the
@@ -4694,30 +4694,30 @@ <h3 class="callout-title">Doing a Dry Run<a class="anchor" aria-label="anchor" h
 <div class="codewrapper sourceCode" id="cb44">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb44-2"><a href="#cb44-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb44-3"><a href="#cb44-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     cat <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
-<span id="cb44-4"><a href="#cb44-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb44-1"><a href="#cb44-1" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb44-2"><a href="#cb44-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb44-3"><a href="#cb44-3" tabindex="-1"></a><span class="op">&gt;</span>     cat <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
+<span id="cb44-4"><a href="#cb44-4" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <p>What is the difference between the two loops below, and which one
 would we want to run?</p>
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Version 1</span></span>
-<span id="cb45-2"><a href="#cb45-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb45-3"><a href="#cb45-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb45-4"><a href="#cb45-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
-<span id="cb45-5"><a href="#cb45-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="co"># Version 1</span></span>
+<span id="cb45-2"><a href="#cb45-2" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb45-3"><a href="#cb45-3" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb45-4"><a href="#cb45-4" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="fu">cat</span> <span class="va">$datafile</span> <span class="op">&gt;&gt;</span> all.pdb</span>
+<span id="cb45-5"><a href="#cb45-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Version 2</span></span>
-<span id="cb46-2"><a href="#cb46-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
-<span id="cb46-3"><a href="#cb46-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb46-4"><a href="#cb46-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="st">"cat </span><span class="va">$datafile</span><span class="st"> &gt;&gt; all.pdb"</span></span>
-<span id="cb46-5"><a href="#cb46-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="co"># Version 2</span></span>
+<span id="cb46-2"><a href="#cb46-2" tabindex="-1"></a><span class="ex">$</span> for datafile in <span class="pp">*</span>.pdb</span>
+<span id="cb46-3"><a href="#cb46-3" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb46-4"><a href="#cb46-4" tabindex="-1"></a><span class="op">&gt;</span>     echo <span class="st">"cat </span><span class="va">$datafile</span><span class="st"> &gt;&gt; all.pdb"</span></span>
+<span id="cb46-5"><a href="#cb46-5" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 </div>
 </div>
@@ -4727,7 +4727,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution7" aria-expanded="false" aria-controls="collapseSolution7">
   <h4 class="accordion-header" id="headingSolution7">Show me the solution</h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
 <div class="accordion-body">
 <p>The second version is the one we want to run. This prints to screen
 everything enclosed in the quote marks, expanding the loop variable name
@@ -4760,13 +4760,13 @@ <h3 class="callout-title">Nested Loops<a class="anchor" aria-label="anchor" href
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> for species in cubane ethane methane</span>
-<span id="cb47-2"><a href="#cb47-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> do</span>
-<span id="cb47-3"><a href="#cb47-3" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     for <span class="ex">temperature</span> in 25 30 37 40</span>
-<span id="cb47-4"><a href="#cb47-4" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     do</span>
-<span id="cb47-5"><a href="#cb47-5" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>         mkdir <span class="va">$species</span><span class="ex">-</span><span class="va">$temperature</span></span>
-<span id="cb47-6"><a href="#cb47-6" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span>     done</span>
-<span id="cb47-7"><a href="#cb47-7" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> for species in cubane ethane methane</span>
+<span id="cb47-2"><a href="#cb47-2" tabindex="-1"></a><span class="op">&gt;</span> do</span>
+<span id="cb47-3"><a href="#cb47-3" tabindex="-1"></a><span class="op">&gt;</span>     for <span class="ex">temperature</span> in 25 30 37 40</span>
+<span id="cb47-4"><a href="#cb47-4" tabindex="-1"></a><span class="op">&gt;</span>     do</span>
+<span id="cb47-5"><a href="#cb47-5" tabindex="-1"></a><span class="op">&gt;</span>         mkdir <span class="va">$species</span><span class="ex">-</span><span class="va">$temperature</span></span>
+<span id="cb47-6"><a href="#cb47-6" tabindex="-1"></a><span class="op">&gt;</span>     done</span>
+<span id="cb47-7"><a href="#cb47-7" tabindex="-1"></a><span class="op">&gt;</span> done</span></code></pre>
 </div>
 </div>
 </div>
@@ -4776,7 +4776,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution8" aria-expanded="false" aria-controls="collapseSolution8">
   <h4 class="accordion-header" id="headingSolution8">Show me the solution</h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
 <div class="accordion-body">
 <p>We have a nested loop, i.e. contained within another loop, so for
 each species in the outer loop, the inner loop (the nested loop)
@@ -4876,8 +4876,8 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd alkanes</span>
-<span id="cb1-2"><a href="#cb1-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> cd alkanes</span>
+<span id="cb1-2"><a href="#cb1-2" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <p>The command <code>nano middle.sh</code> opens the file
 <code>middle.sh</code> within the text editor ‘nano’ (which runs within
@@ -4899,7 +4899,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4912,12 +4912,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 <p>Sure enough, our script’s output is exactly what we would get if we
 ran that pipeline directly.</p>
-<div id="text-vs.-whatever" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="text-vs.-whatever" class="callout-inner">
-<h3 class="callout-title">Text vs. Whatever<a class="anchor" aria-label="anchor" href="#text-vs.-whatever"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="text-vs--whatever">Text vs. Whatever<a class="anchor" aria-label="anchor" href="#text-vs--whatever"></a>
 </h3>
 <div class="callout-content">
 <p>We usually call programs like Microsoft Word or LibreOffice Writer
@@ -4941,7 +4941,7 @@ <h3 class="callout-title">Text vs. Whatever<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <p>Now, within “nano”, replace the text <code>octane.pdb</code> with the
 special variable called <code>$1</code>:</p>
@@ -4952,7 +4952,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh octane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh octane.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4967,7 +4967,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4978,12 +4978,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 ATOM     12  H           1      -0.048  -1.362  -0.205  1.00  0.00
 ATOM     13  H           1      -1.183   0.500  -1.412  1.00  0.00</code></pre>
 </div>
-<div id="double-quotes-around-arguments" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="double-quotes-around-arguments" class="callout-inner">
-<h3 class="callout-title">Double-Quotes Around Arguments<a class="anchor" aria-label="anchor" href="#double-quotes-around-arguments"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="double-quotes-around-arguments">Double-Quotes Around Arguments<a class="anchor" aria-label="anchor" href="#double-quotes-around-arguments"></a>
 </h3>
 <div class="callout-content">
 <p>For the same reason that we put the loop variable inside
@@ -5005,14 +5005,14 @@ <h3 class="callout-title">Double-Quotes Around Arguments<a class="anchor" aria-l
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <pre class="source"><code>head -n "$2" "$1" | tail -n "$3"</code></pre>
 <p>We can now run:</p>
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 15 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 15 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5028,7 +5028,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 20 5</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> bash middle.sh pentane.pdb 20 5</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5046,7 +5046,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">$</span> nano middle.sh</span></code></pre>
 </div>
 <pre class="source"><code># Select lines from the middle of a file.
 # Usage: bash middle.sh filename end_line num_lines
@@ -5063,7 +5063,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="pp">*</span>.pdb <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
 </div>
 <p>because <code>wc -l</code> lists the number of lines in the files
 (recall that <code>wc</code> stands for ‘word count’, adding the
@@ -5083,7 +5083,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb20">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano sorted.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> nano sorted.sh</span></code></pre>
 </div>
 <pre class="source"><code># Sort files by their length.
 # Usage: bash sorted.sh one_or_more_filenames
@@ -5091,7 +5091,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb22">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash sorted.sh <span class="pp">*</span>.pdb ../creatures/<span class="pp">*</span>.dat</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> bash sorted.sh <span class="pp">*</span>.pdb ../creatures/<span class="pp">*</span>.dat</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5149,16 +5149,16 @@ <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script to find unique species in csv files where species is the second data field</span></span>
-<span id="cb25-2"><a href="#cb25-2" aria-hidden="true" tabindex="-1"></a><span class="co"># This script accepts any number of file names as command line arguments</span></span>
-<span id="cb25-3"><a href="#cb25-3" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb25-4"><a href="#cb25-4" aria-hidden="true" tabindex="-1"></a><span class="co"># Loop over all files</span></span>
-<span id="cb25-5"><a href="#cb25-5" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> file <span class="kw">in</span> <span class="va">$@</span></span>
-<span id="cb25-6"><a href="#cb25-6" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb25-7"><a href="#cb25-7" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="st">"Unique species in </span><span class="va">$file</span><span class="st">:"</span></span>
-<span id="cb25-8"><a href="#cb25-8" aria-hidden="true" tabindex="-1"></a>    <span class="co"># Extract species names</span></span>
-<span id="cb25-9"><a href="#cb25-9" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 2 <span class="va">$file</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span>
-<span id="cb25-10"><a href="#cb25-10" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="co"># Script to find unique species in csv files where species is the second data field</span></span>
+<span id="cb25-2"><a href="#cb25-2" tabindex="-1"></a><span class="co"># This script accepts any number of file names as command line arguments</span></span>
+<span id="cb25-3"><a href="#cb25-3" tabindex="-1"></a></span>
+<span id="cb25-4"><a href="#cb25-4" tabindex="-1"></a><span class="co"># Loop over all files</span></span>
+<span id="cb25-5"><a href="#cb25-5" tabindex="-1"></a><span class="cf">for</span> file <span class="kw">in</span> <span class="va">$@</span></span>
+<span id="cb25-6"><a href="#cb25-6" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb25-7"><a href="#cb25-7" tabindex="-1"></a>    <span class="bu">echo</span> <span class="st">"Unique species in </span><span class="va">$file</span><span class="st">:"</span></span>
+<span id="cb25-8"><a href="#cb25-8" tabindex="-1"></a>    <span class="co"># Extract species names</span></span>
+<span id="cb25-9"><a href="#cb25-9" tabindex="-1"></a>    <span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 2 <span class="va">$file</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="kw">|</span> <span class="fu">uniq</span></span>
+<span id="cb25-10"><a href="#cb25-10" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 </div>
 </div>
@@ -5172,7 +5172,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> redo-figure-3.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> redo-figure-3.sh</span></code></pre>
 </div>
 <p>The file <code>redo-figure-3.sh</code> now contains:</p>
 <pre class="source"><code>297 bash goostats.sh NENE01729B.txt stats-NENE01729B.txt
@@ -5197,7 +5197,7 @@ <h3 class="callout-title">Why Record Commands in the History Before
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> recent.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">$</span> history <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 5 <span class="op">&gt;</span> recent.sh</span></code></pre>
 </div>
 <p>the last command in the file is the <code>history</code> command
 itself, i.e., the shell has added <code>history</code> to the command
@@ -5238,37 +5238,37 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb29">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd ../../north-pacific-gyre/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="ex">$</span> cd ../../north-pacific-gyre/</span></code></pre>
 </div>
 <p>She creates a file using <code>nano</code> …</p>
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> nano do-stats.sh</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> nano do-stats.sh</span></code></pre>
 </div>
 <p>…which contains the following:</p>
 <div class="codewrapper sourceCode" id="cb31">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
-<span id="cb31-2"><a href="#cb31-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
-<span id="cb31-3"><a href="#cb31-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb31-4"><a href="#cb31-4" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
-<span id="cb31-5"><a href="#cb31-5" aria-hidden="true" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb31-6"><a href="#cb31-6" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb31-1"><a href="#cb31-1" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
+<span id="cb31-2"><a href="#cb31-2" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
+<span id="cb31-3"><a href="#cb31-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb31-4"><a href="#cb31-4" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
+<span id="cb31-5"><a href="#cb31-5" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb31-6"><a href="#cb31-6" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <p>She saves this in a file called <code>do-stats.sh</code> so that she
 can now re-do the first stage of her analysis by typing:</p>
 <div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
 </div>
 <p>She can also do this:</p>
 <div class="codewrapper sourceCode" id="cb33">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt <span class="kw">|</span> <span class="fu">wc</span> <span class="at">-l</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb33-1"><a href="#cb33-1" tabindex="-1"></a><span class="ex">$</span> bash do-stats.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt <span class="kw">|</span> <span class="fu">wc</span> <span class="at">-l</span></span></code></pre>
 </div>
 <p>so that the output is just the number of files processed rather than
 the names of the files that were processed.</p>
@@ -5278,12 +5278,12 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Calculate stats for Site A and Site B data files.</span></span>
-<span id="cb34-2"><a href="#cb34-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
-<span id="cb34-3"><a href="#cb34-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb34-4"><a href="#cb34-4" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
-<span id="cb34-5"><a href="#cb34-5" aria-hidden="true" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb34-6"><a href="#cb34-6" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="co"># Calculate stats for Site A and Site B data files.</span></span>
+<span id="cb34-2"><a href="#cb34-2" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span>
+<span id="cb34-3"><a href="#cb34-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb34-4"><a href="#cb34-4" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datafile</span></span>
+<span id="cb34-5"><a href="#cb34-5" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb34-6"><a href="#cb34-6" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <p>The advantage is that this always selects the right files: she
 doesn’t have to remember to exclude the ‘Z’ files. The disadvantage is
@@ -5308,15 +5308,15 @@ <h3 class="callout-title">Variables in Shell Scripts<a class="anchor" aria-label
 <div class="codewrapper sourceCode" id="cb35">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" aria-hidden="true" tabindex="-1"></a><span class="fu">head</span> <span class="at">-n</span> <span class="va">$2</span> <span class="va">$1</span></span>
-<span id="cb35-2"><a href="#cb35-2" aria-hidden="true" tabindex="-1"></a><span class="fu">tail</span> <span class="at">-n</span> <span class="va">$3</span> <span class="va">$1</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb35-1"><a href="#cb35-1" tabindex="-1"></a><span class="fu">head</span> <span class="at">-n</span> <span class="va">$2</span> <span class="va">$1</span></span>
+<span id="cb35-2"><a href="#cb35-2" tabindex="-1"></a><span class="fu">tail</span> <span class="at">-n</span> <span class="va">$3</span> <span class="va">$1</span></span></code></pre>
 </div>
 <p>While you are in the <code>alkanes</code> directory, you type the
 following command:</p>
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash script.sh <span class="st">'*.pdb'</span> 1 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> bash script.sh <span class="st">'*.pdb'</span> 1 1</span></code></pre>
 </div>
 <p>Which of the following outputs would you expect to see?</p>
 <ol style="list-style-type: decimal">
@@ -5346,8 +5346,8 @@ <h4 class="accordion-header" id="headingSolution3">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb37">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span>
-<span id="cb37-2"><a href="#cb37-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb37-1"><a href="#cb37-1" tabindex="-1"></a><span class="ex">$</span> head <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span>
+<span id="cb37-2"><a href="#cb37-2" tabindex="-1"></a><span class="ex">$</span> tail <span class="at">-n</span> 1 cubane.pdb ethane.pdb octane.pdb pentane.pdb propane.pdb</span></code></pre>
 </div>
 <p>The shell does not expand <code>'*.pdb'</code> because it is enclosed
 by quote marks. As such, the first argument to the script is
@@ -5373,7 +5373,7 @@ <h3 class="callout-title">Find the Longest File With a Given
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/alkanes pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/alkanes pdb</span></code></pre>
 </div>
 <p>would print the name of the <code>.pdb</code> file in
 <code>shell-lesson-data/exercise-data/alkanes</code> that has the most
@@ -5382,7 +5382,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/writing txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">$</span> bash longest.sh shell-lesson-data/exercise-data/writing txt</span></code></pre>
 </div>
 </div>
 </div>
@@ -5397,13 +5397,13 @@ <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb40">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Shell script which takes two arguments:</span></span>
-<span id="cb40-2"><a href="#cb40-2" aria-hidden="true" tabindex="-1"></a><span class="co">#    1. a directory name</span></span>
-<span id="cb40-3"><a href="#cb40-3" aria-hidden="true" tabindex="-1"></a><span class="co">#    2. a file extension</span></span>
-<span id="cb40-4"><a href="#cb40-4" aria-hidden="true" tabindex="-1"></a><span class="co"># and prints the name of the file in that directory</span></span>
-<span id="cb40-5"><a href="#cb40-5" aria-hidden="true" tabindex="-1"></a><span class="co"># with the most lines which matches the file extension.</span></span>
-<span id="cb40-6"><a href="#cb40-6" aria-hidden="true" tabindex="-1"></a></span>
-<span id="cb40-7"><a href="#cb40-7" aria-hidden="true" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$1</span>/<span class="pp">*</span>.<span class="va">$2</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 2 <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" tabindex="-1"></a><span class="co"># Shell script which takes two arguments:</span></span>
+<span id="cb40-2"><a href="#cb40-2" tabindex="-1"></a><span class="co">#    1. a directory name</span></span>
+<span id="cb40-3"><a href="#cb40-3" tabindex="-1"></a><span class="co">#    2. a file extension</span></span>
+<span id="cb40-4"><a href="#cb40-4" tabindex="-1"></a><span class="co"># and prints the name of the file in that directory</span></span>
+<span id="cb40-5"><a href="#cb40-5" tabindex="-1"></a><span class="co"># with the most lines which matches the file extension.</span></span>
+<span id="cb40-6"><a href="#cb40-6" tabindex="-1"></a></span>
+<span id="cb40-7"><a href="#cb40-7" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$1</span>/<span class="pp">*</span>.<span class="va">$2</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span> <span class="kw">|</span> <span class="fu">tail</span> <span class="at">-n</span> 2 <span class="kw">|</span> <span class="fu">head</span> <span class="at">-n</span> 1</span></code></pre>
 </div>
 <p>The first part of the pipeline, <code>wc -l $1/*.$2 | sort -n</code>,
 counts the lines in each file and sorts them numerically (largest last).
@@ -5436,23 +5436,23 @@ <h3 class="callout-title">Script Reading Comprehension<a class="anchor" aria-lab
 <div class="codewrapper sourceCode" id="cb41">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script 1</span></span>
-<span id="cb41-2"><a href="#cb41-2" aria-hidden="true" tabindex="-1"></a><span class="bu">echo</span> <span class="pp">*</span>.<span class="pp">*</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb41-1"><a href="#cb41-1" tabindex="-1"></a><span class="co"># Script 1</span></span>
+<span id="cb41-2"><a href="#cb41-2" tabindex="-1"></a><span class="bu">echo</span> <span class="pp">*</span>.<span class="pp">*</span></span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script 2</span></span>
-<span id="cb42-2"><a href="#cb42-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> filename <span class="kw">in</span> <span class="va">$1</span> <span class="va">$2</span> <span class="va">$3</span></span>
-<span id="cb42-3"><a href="#cb42-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb42-4"><a href="#cb42-4" aria-hidden="true" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$filename</span></span>
-<span id="cb42-5"><a href="#cb42-5" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="co"># Script 2</span></span>
+<span id="cb42-2"><a href="#cb42-2" tabindex="-1"></a><span class="cf">for</span> filename <span class="kw">in</span> <span class="va">$1</span> <span class="va">$2</span> <span class="va">$3</span></span>
+<span id="cb42-3"><a href="#cb42-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb42-4"><a href="#cb42-4" tabindex="-1"></a>    <span class="fu">cat</span> <span class="va">$filename</span></span>
+<span id="cb42-5"><a href="#cb42-5" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Script 3</span></span>
-<span id="cb43-2"><a href="#cb43-2" aria-hidden="true" tabindex="-1"></a><span class="bu">echo</span> <span class="va">$@</span>.pdb</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="co"># Script 3</span></span>
+<span id="cb43-2"><a href="#cb43-2" tabindex="-1"></a><span class="bu">echo</span> <span class="va">$@</span>.pdb</span></code></pre>
 </div>
 </div>
 </div>
@@ -5500,26 +5500,26 @@ <h3 class="callout-title">Debugging Scripts<a class="anchor" aria-label="anchor"
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
-<span id="cb45-2"><a href="#cb45-2" aria-hidden="true" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
-<span id="cb45-3"><a href="#cb45-3" aria-hidden="true" tabindex="-1"></a><span class="cf">do</span></span>
-<span id="cb45-4"><a href="#cb45-4" aria-hidden="true" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datfile</span></span>
-<span id="cb45-5"><a href="#cb45-5" aria-hidden="true" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
-<span id="cb45-6"><a href="#cb45-6" aria-hidden="true" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="co"># Calculate stats for data files.</span></span>
+<span id="cb45-2"><a href="#cb45-2" tabindex="-1"></a><span class="cf">for</span> datafile <span class="kw">in</span> <span class="st">"</span><span class="va">$@</span><span class="st">"</span></span>
+<span id="cb45-3"><a href="#cb45-3" tabindex="-1"></a><span class="cf">do</span></span>
+<span id="cb45-4"><a href="#cb45-4" tabindex="-1"></a>    <span class="bu">echo</span> <span class="va">$datfile</span></span>
+<span id="cb45-5"><a href="#cb45-5" tabindex="-1"></a>    <span class="fu">bash</span> goostats.sh <span class="va">$datafile</span> stats-<span class="va">$datafile</span></span>
+<span id="cb45-6"><a href="#cb45-6" tabindex="-1"></a><span class="cf">done</span></span></code></pre>
 </div>
 <p>When you run it from the <code>north-pacific-gyre</code>
 directory:</p>
 <div class="codewrapper sourceCode" id="cb46">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb46-1"><a href="#cb46-1" tabindex="-1"></a><span class="ex">$</span> bash do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
 </div>
 <p>the output is blank. To figure out why, re-run the script using the
 <code>-x</code> option:</p>
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash <span class="at">-x</span> do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> bash <span class="at">-x</span> do-errors.sh NENE<span class="pp">*</span>A.txt NENE<span class="pp">*</span>B.txt</span></code></pre>
 </div>
 <p>What is the output showing you? Which line is responsible for the
 error?</p>
@@ -5629,9 +5629,9 @@ <h3 class="card-title">Objectives</h3>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd</span>
-<span id="cb1-2"><a href="#cb1-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data/writing</span>
-<span id="cb1-3"><a href="#cb1-3" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cat haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> cd</span>
+<span id="cb1-2"><a href="#cb1-2" tabindex="-1"></a><span class="ex">$</span> cd Desktop/shell-lesson-data/exercise-data/writing</span>
+<span id="cb1-3"><a href="#cb1-3" tabindex="-1"></a><span class="ex">$</span> cat haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5652,7 +5652,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep not haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> grep not haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5675,7 +5675,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep The haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> grep The haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5694,7 +5694,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> The haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> The haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5708,7 +5708,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> <span class="st">"is not"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-w</span> <span class="st">"is not"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5725,7 +5725,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="st">"it"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="st">"it"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5743,7 +5743,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb13">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5756,7 +5756,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb15">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-i</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-i</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5771,7 +5771,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb17">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-v</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-n</span> <span class="at">-w</span> <span class="at">-v</span> <span class="st">"the"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5794,7 +5794,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb19">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-r</span> Yesterday .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-r</span> Yesterday .</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5809,7 +5809,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">--help</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">--help</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5871,12 +5871,12 @@ <h4 class="accordion-header" id="headingSolution1">Show me the solution</h4>
 </div>
 </div>
 </div>
-<div id="wildcards" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="wildcards" class="callout-inner">
-<h3 class="callout-title">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="wildcards">Wildcards<a class="anchor" aria-label="anchor" href="#wildcards"></a>
 </h3>
 <div class="callout-content">
 <p><code>grep</code>‘s real power doesn’t come from its options, though;
@@ -5890,7 +5890,7 @@ <h3 class="callout-title">Wildcards<a class="anchor" aria-label="anchor" href="#
 <div class="codewrapper sourceCode" id="cb24">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-E</span> <span class="st">"^.o"</span> haiku.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="at">-E</span> <span class="st">"^.o"</span> haiku.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -5941,13 +5941,13 @@ <h3 class="callout-title">Tracking a Species<a class="anchor" aria-label="anchor
 <div class="codewrapper sourceCode" id="cb28">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" aria-hidden="true" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> : <span class="at">-f</span> 2</span>
-<span id="cb28-2"><a href="#cb28-2" aria-hidden="true" tabindex="-1"></a><span class="op">&gt;</span></span>
-<span id="cb28-3"><a href="#cb28-3" aria-hidden="true" tabindex="-1"></a><span class="kw">|</span></span>
-<span id="cb28-4"><a href="#cb28-4" aria-hidden="true" tabindex="-1"></a><span class="fu">grep</span> <span class="at">-w</span> <span class="va">$1</span> <span class="at">-r</span> <span class="va">$2</span></span>
-<span id="cb28-5"><a href="#cb28-5" aria-hidden="true" tabindex="-1"></a><span class="kw">|</span></span>
-<span id="cb28-6"><a href="#cb28-6" aria-hidden="true" tabindex="-1"></a><span class="va">$1</span><span class="ex">.txt</span></span>
-<span id="cb28-7"><a href="#cb28-7" aria-hidden="true" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 1,3</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> : <span class="at">-f</span> 2</span>
+<span id="cb28-2"><a href="#cb28-2" tabindex="-1"></a><span class="op">&gt;</span></span>
+<span id="cb28-3"><a href="#cb28-3" tabindex="-1"></a><span class="kw">|</span></span>
+<span id="cb28-4"><a href="#cb28-4" tabindex="-1"></a><span class="fu">grep</span> <span class="at">-w</span> <span class="va">$1</span> <span class="at">-r</span> <span class="va">$2</span></span>
+<span id="cb28-5"><a href="#cb28-5" tabindex="-1"></a><span class="kw">|</span></span>
+<span id="cb28-6"><a href="#cb28-6" tabindex="-1"></a><span class="va">$1</span><span class="ex">.txt</span></span>
+<span id="cb28-7"><a href="#cb28-7" tabindex="-1"></a><span class="fu">cut</span> <span class="at">-d</span> , <span class="at">-f</span> 1,3</span></code></pre>
 </div>
 <p>Hint: use <code>man grep</code> to look for how to grep text
 recursively in a directory and <code>man cut</code> to select more than
@@ -5973,7 +5973,7 @@ <h4 class="accordion-header" id="headingSolution2">Show me the solution</h4>
 <div class="codewrapper sourceCode" id="cb30">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> bash count-species.sh bear .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">$</span> bash count-species.sh bear .</span></code></pre>
 </div>
 </div>
 </div>
@@ -6073,7 +6073,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find .</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">$</span> find .</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -6109,7 +6109,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> d</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> d</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -6126,7 +6126,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> f</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-type</span> f</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -6149,7 +6149,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb40">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="pp">*</span>.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb40-1"><a href="#cb40-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="pp">*</span>.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -6164,7 +6164,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb42">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> numbers.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb42-1"><a href="#cb42-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> numbers.txt</span></code></pre>
 </div>
 <p><code>find</code> did what we asked; we just asked for the wrong
 thing.</p>
@@ -6176,7 +6176,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb43">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="st">"*.txt"</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb43-1"><a href="#cb43-1" tabindex="-1"></a><span class="ex">$</span> find . <span class="at">-name</span> <span class="st">"*.txt"</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -6185,12 +6185,12 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <span><span class="va">.</span><span class="op">/</span><span class="va">writing</span><span class="op">/</span><span class="va">haiku.txt</span></span>
 <span><span class="va">.</span><span class="op">/</span><span class="va">numbers.txt</span></span></code></pre>
 </div>
-<div id="listing-vs.-finding" class="callout callout">
+<div id="callout2" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="listing-vs.-finding" class="callout-inner">
-<h3 class="callout-title">Listing vs. Finding<a class="anchor" aria-label="anchor" href="#listing-vs.-finding"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="listing-vs--finding">Listing vs. Finding<a class="anchor" aria-label="anchor" href="#listing-vs--finding"></a>
 </h3>
 <div class="callout-content">
 <p><code>ls</code> and <code>find</code> can be made to do similar
@@ -6210,7 +6210,7 @@ <h3 class="callout-title">Listing vs. Finding<a class="anchor" aria-label="anch
 <div class="codewrapper sourceCode" id="cb45">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb45-1"><a href="#cb45-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -6230,7 +6230,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb47">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> ./writing/LittleWomen.txt ./writing/haiku.txt ./numbers.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb47-1"><a href="#cb47-1" tabindex="-1"></a><span class="ex">$</span> wc <span class="at">-l</span> ./writing/LittleWomen.txt ./writing/haiku.txt ./numbers.txt</span></code></pre>
 </div>
 <p>which is what we wanted. This expansion is exactly what the shell
 does when it expands wildcards like <code>*</code> and <code>?</code>,
@@ -6244,7 +6244,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb48">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> grep <span class="st">"searching"</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb48-1"><a href="#cb48-1" tabindex="-1"></a><span class="ex">$</span> grep <span class="st">"searching"</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.txt"</span><span class="va">)</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -6296,12 +6296,12 @@ <h4 class="accordion-header" id="headingSolution4">Show me the solution</h4>
 </div>
 </div>
 </div>
-<div id="binary-files" class="callout callout">
+<div id="callout3" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="binary-files" class="callout-inner">
-<h3 class="callout-title">Binary Files<a class="anchor" aria-label="anchor" href="#binary-files"></a>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="binary-files">Binary Files<a class="anchor" aria-label="anchor" href="#binary-files"></a>
 </h3>
 <div class="callout-content">
 <p>We have focused exclusively on finding patterns in text files. What
@@ -6347,7 +6347,7 @@ <h3 class="callout-title">
 <div class="codewrapper sourceCode" id="cb50">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" aria-hidden="true" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.dat"</span><span class="va">)</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb50-1"><a href="#cb50-1" tabindex="-1"></a><span class="fu">wc</span> <span class="at">-l</span> <span class="va">$(</span><span class="fu">find</span> . <span class="at">-name</span> <span class="st">"*.dat"</span><span class="va">)</span> <span class="kw">|</span> <span class="fu">sort</span> <span class="at">-n</span></span></code></pre>
 </div>
 </div>
 </div>
@@ -6443,8 +6443,8 @@ <h3 class="callout-title">Key Points<a class="anchor" aria-label="anchor" href="
   "url": "https://swcarpentry.github.io/shell-novice/instructor/aio.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/aio.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-02-27",
-  "datePublished": "2024-02-27"
+  "dateModified": "2024-03-05",
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/discuss.html b/instructor/discuss.html
index c2ac7d23c..875a21ed4 100644
--- a/instructor/discuss.html
+++ b/instructor/discuss.html
@@ -391,7 +391,7 @@ <h1>Discussion</h1>
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/discuss.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-05-02",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/images.html b/instructor/images.html
index 50182884c..7c9a42780 100644
--- a/instructor/images.html
+++ b/instructor/images.html
@@ -392,8 +392,8 @@ <h3 id="05-loop-figure-1">Figure 1</h3>
   "url": "https://swcarpentry.github.io/shell-novice/instructor/images.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/images.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-02-27",
-  "datePublished": "2024-02-27"
+  "dateModified": "2024-03-05",
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/index.html b/instructor/index.html
index fd781df14..ab22b712f 100644
--- a/instructor/index.html
+++ b/instructor/index.html
@@ -385,14 +385,13 @@ <h3 class="callout-title">Prerequisites<a class="anchor" aria-label="anchor" hre
 folder as your working directory.</li>
 </ol><p>In the lesson, you will find out how to access the data files in this
 folder.</p>
-<div id="where-to-type-commands-how-to-open-a-new-shell" class="callout callout">
+<div id="callout1" class="callout">
 <div class="callout-square">
 <i class="callout-icon" data-feather="bell"></i>
 </div>
-<div id="where-to-type-commands-how-to-open-a-new-shell" class="callout-inner">
-<h3 class="callout-title">Where to type commands: How to open a new
-shell<a class="anchor" aria-label="anchor" href="#where-to-type-commands-how-to-open-a-new-shell"></a>
-</h3>
+<div class="section level3 callout-title callout-inner">
+<h3 class="callout-title" id="where-to-type-commands-how-to-open-a-new-shell">Where to type commands: How to open a new
+shell<a class="anchor" aria-label="anchor" href="#where-to-type-commands-how-to-open-a-new-shell"></a></h3>
 <div class="callout-content">
 <p>The shell is a program that enables us to send commands to the
 computer and receive output. It is also referred to as the terminal or
@@ -525,8 +524,8 @@ <h4 class="accordion-header" id="headingSolution3">Linux</h4>
   "url": "https://swcarpentry.github.io/shell-novice/instructor/index.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/index.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-02-27",
-  "datePublished": "2024-02-27"
+  "dateModified": "2024-03-05",
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/instructor-notes.html b/instructor/instructor-notes.html
index bf3b0444b..765599f03 100644
--- a/instructor/instructor-notes.html
+++ b/instructor/instructor-notes.html
@@ -490,7 +490,7 @@ <h1>Instructor Notes</h1>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="va">PS1</span><span class="op">=</span><span class="st">'$ '</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="va">PS1</span><span class="op">=</span><span class="st">'$ '</span></span></code></pre>
 </div>
 </li>
 <li><p>On Windows machines if <code>nano</code> hasn’t been properly
@@ -505,8 +505,8 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb2">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd</span>
-<span id="cb2-2"><a href="#cb2-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd Desktop</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb2-1"><a href="#cb2-1" tabindex="-1"></a><span class="ex">$</span> cd</span>
+<span id="cb2-2"><a href="#cb2-2" tabindex="-1"></a><span class="ex">$</span> cd Desktop</span></code></pre>
 </div>
 <p>will always put someone on their desktop (unless their machine is
 backed up using enterprise OneDrive, see next point). Have them create
@@ -523,8 +523,8 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd <span class="st">"~/OneDrive - Name Of Enterprise/Desktop"</span></span>
-<span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a><span class="ex">$</span> cd <span class="st">"C:/Users/Username/OneDrive - Name Of Enterprise/Desktop"</span></span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> cd <span class="st">"~/OneDrive - Name Of Enterprise/Desktop"</span></span>
+<span id="cb3-2"><a href="#cb3-2" tabindex="-1"></a><span class="ex">$</span> cd <span class="st">"C:/Users/Username/OneDrive - Name Of Enterprise/Desktop"</span></span></code></pre>
 </div>
 <p>One way to spot if the computer is using this kind of configuration
 is to look at files, folders or links on the desktop. Usually the icon
@@ -652,8 +652,8 @@ <h3 id="03-create-headingInstructor1">
   "url": "https://swcarpentry.github.io/shell-novice/instructor/instructor-notes.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/instructor-notes.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-02-27",
-  "datePublished": "2024-02-27"
+  "dateModified": "2024-03-05",
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/key-points.html b/instructor/key-points.html
index 7b01fd87b..4b5760af1 100644
--- a/instructor/key-points.html
+++ b/instructor/key-points.html
@@ -512,8 +512,8 @@ <h2 class="accordion-header" id="flush-headingTwelve">
   "url": "https://swcarpentry.github.io/shell-novice/instructor/key-points.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/key-points.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-02-27",
-  "datePublished": "2024-02-27"
+  "dateModified": "2024-03-05",
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/profiles.html b/instructor/profiles.html
index e5789b6d7..9ff0a5ae5 100644
--- a/instructor/profiles.html
+++ b/instructor/profiles.html
@@ -288,8 +288,8 @@ <h1>Learner Profiles</h1>
   "url": "https://swcarpentry.github.io/shell-novice/instructor/profiles.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/profiles.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-02-27",
-  "datePublished": "2024-02-27"
+  "dateModified": "2024-03-05",
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/instructor/reference.html b/instructor/reference.html
index 813c828b8..01d296bb9 100644
--- a/instructor/reference.html
+++ b/instructor/reference.html
@@ -634,7 +634,7 @@ <h3 id="miscellaneous">Miscellaneous<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/reference.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-07-23",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/key-points.html b/key-points.html
index a91619345..c296cb3e9 100644
--- a/key-points.html
+++ b/key-points.html
@@ -510,8 +510,8 @@ <h2 class="accordion-header" id="flush-headingTwelve">
   "url": "https://swcarpentry.github.io/shell-novice/key-points.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/key-points.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-02-27",
-  "datePublished": "2024-02-27"
+  "dateModified": "2024-03-05",
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/pkgdown.yml b/pkgdown.yml
index 7d94b2dea..7a98c17f7 100644
--- a/pkgdown.yml
+++ b/pkgdown.yml
@@ -1,6 +1,6 @@
-pandoc: 2.19.2
+pandoc: 3.1.11
 pkgdown: 2.0.7
 pkgdown_sha: ~
 articles: {}
-last_built: 2024-02-27T00:24Z
+last_built: 2024-03-05T00:22Z
 
diff --git a/profiles.html b/profiles.html
index d7235e2cb..75d0d6cee 100644
--- a/profiles.html
+++ b/profiles.html
@@ -288,8 +288,8 @@ <h1>Learner Profiles</h1>
   "url": "https://swcarpentry.github.io/shell-novice/profiles.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/profiles.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-02-27",
-  "datePublished": "2024-02-27"
+  "dateModified": "2024-03-05",
+  "datePublished": "2024-03-05"
 }
 
   </script><script>
diff --git a/reference.html b/reference.html
index 950690c15..57de5c22f 100644
--- a/reference.html
+++ b/reference.html
@@ -632,7 +632,7 @@ <h3 id="miscellaneous">Miscellaneous<a class="anchor" aria-label="anchor" href="
   "identifier": "https://swcarpentry.github.io/shell-novice/reference.html",
   "dateCreated": "2014-10-22",
   "dateModified": "2023-07-23",
-  "datePublished": "2024-02-27"
+  "datePublished": "2024-03-05"
 }
 
   </script><script>