Added new module.

Makefile

@@ -5,7 +5,8 @@ obj-m += hello.o \
 		 hello-5.o \
 		 chardev.o \
 		 procfs.o \
-		 procfs2.o
+		 procfs2.o \
+		 procfs3.o
 
 MAKE = /usr/bin/make
 

README.md

@@ -13,6 +13,7 @@ Reference: [The LKM programming Guide](https://www.tldp.org/LDP/lkmpg/2.6/lkmpg.
 5. Simple Character Device Driver.
 6. /proc File System Module.
 7. /proc using Standard File System.
+8. Managing procfs with seq_file.
 
 ### Some useful StackOverflow Threads:
 1. [proc_root](https://stackoverflow.com/questions/2531730/linux-kernel-module-creating-proc-file-proc-root-undeclared-error)

procfs3.c

@@ -0,0 +1,90 @@
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+
+#define PROC_NAME "iter"
+
+MODULE_AUTHOR("Arna Maity <[email protected]>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Module illustrating the management of procfs using seq_file.");
+
+// Prototypes for Module Entry & Exit functions.
+static int __init procfs3_init(void);
+static void __exit procfs3_exit(void);
+
+struct proc_dir_entry* entry;
+
+static void* my_seq_start(struct seq_file* s, loff_t* pos)
+{
+    static unsigned long counter = 0;
+    if(*pos == 0)
+        return &counter;
+
+    else{
+        *pos = 0;
+        return NULL;
+    }
+}
+
+static void* my_seq_next(struct seq_file* s, void* v, loff_t* pos)
+{
+    unsigned long *tmp_v = (unsigned long*)v;
+    (*tmp_v)++;
+    (*pos)++;
+    return NULL;
+}
+
+static void my_seq_stop(struct seq_file* s, void* v)
+{
+
+}
+
+static int my_seq_show(struct seq_file* s, void* v)
+{
+    loff_t* spos = (loff_t*)v;
+    seq_printf(s,"%Ld\n",*spos);
+
+    return 0;
+}
+
+/*  This Structure gathers "functions" to manage the sequence. 
+ */
+static struct seq_operations my_seq_ops = {
+    .start = my_seq_start,
+    .next = my_seq_next,
+    .stop = my_seq_stop,
+    .show = my_seq_show
+};
+
+/*  This function is called when the /proc file is opened. 
+ */
+
+static int my_open(struct inode* inode, struct file* file)
+{
+    return seq_open(file, &my_seq_ops);
+}
+
+/*  This structure gathers all the functions to manage the /proc file. 
+ */
+ static struct file_operations my_file_ops = {
+     .owner = THIS_MODULE,
+     .open = my_open,
+     .read = seq_read,
+     .llseek = seq_lseek,
+     .release = seq_release
+ };
+
+static int __init procfs3_init(void)
+{
+    entry = proc_create(PROC_NAME,0,NULL,&my_file_ops);
+    return 0;
+}
+
+static void __exit procfs3_exit(void)
+{
+    proc_remove(entry);
+}
+
+module_init(procfs3_init);
+module_exit(procfs3_exit);