lab9

#!/bin/ksh
# Author: Wolfgang C. Strack
# CIS18C Lab 9 script

########## initialize some global variables
usageMessage="Usage: $0 directoryName"

########## functions
checkIfValidDir () # takes a filename as an argument
{
	if [ ! -d "$1" ]; then
		echo "Error: $1 is not a directory"
		exit 1
	fi

	# cd to directory argument
	cd $1

	if [ ! $(pwd -P | egrep "/home/(student|staff)/$USER" &> /dev/null) ]; then
		echo "Error: `pwd -P` is not your home directory or any of its subdirectories"
		exit 1
	fi
}

# decided to make this a function
# so there's less clutter in main
getListOfMatchingFiles ()
{
	for file in *; do
		head -1 $file 2> /dev/null | egrep '#!/bin/bash' > /dev/null
		if [ $? -eq 0 ]; then
			listOfMatchingFiles=(${listOfMatchingFiles[@]} $file)
		fi
	done
}

printMatchingFiles () # takes an array of matching file names as arguments
{
	trap '' SIGINT

	echo "Total number of files in $(pwd -P) : $(ls | wc -l)"
	echo "Total number of files in $(pwd -P) that are bash scripts: $#"
	echo "Now printing names of files that are bash scripts:"
	echo

	for filename in "$@"; do
		echo $filename
		sleep 3
	done

	trap - SIGINT # reset signal handling to default
}

########## main
if [ $# -ne 1 ]; then
	echo $usageMessage
	exit 1
fi

checkIfValidDir $1 # changes to directory if valid, else exits script
getListOfMatchingFiles # see function above

if [ ${#listOfMatchingFiles[@]} -eq 0 ]; then
	echo "No files in $(pwd -P) are bash scripts"
else
	printMatchingFiles ${listOfMatchingFiles[@]}
fi