#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/proc_fs.h>
#include<linux/sched.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <linux/slab.h>

#define PROC_FILE_NAME "testfile"

#define MESSAGE "I have two cats in my garage, named Zeke and Tabby\n"
size_t mlen;

ssize_t read_simple(struct file *filp, char *buf, size_t count, loff_t *offp ) {
	if(*offp < mlen) { // If we have data to deliver
		size_t quantity = mlen - *offp;
		if(count < quantity)
			quantity = count;
		memcpy(buf, MESSAGE + *offp, quantity);
		*offp += quantity;
		return quantity;
	} else {
		return 0;
	}
}

int open_our_file(struct inode * the_inode, struct file *the_file){
	printk("Open was called\n");
	return 0;
}

/* On older kernels, you need to use a file_operations structure instead
 * Like this:
 *	struct file_operations proc_fops = {
 *		read: read_simple,
 *		open: open_our_file,
 *	};
 *	Other than that, it's the same!
 */

struct proc_ops proc_fops = {
	proc_read: read_simple,
	proc_open: open_our_file,
};


int init_module (void) {
	printk("We're in the kernel!\n");
	mlen = strlen(MESSAGE);
	proc_create(PROC_FILE_NAME,0,NULL,&proc_fops);
	return 0;
}

void cleanup_module(void) {
	remove_proc_entry(PROC_FILE_NAME,NULL);
}

MODULE_LICENSE("GPL");