#include <linux/module.h>
#include <linux/init.h>
#include <linux/proc_fs.h>

MODULE_LICENSE("GPL");

ssize_t demo_read(struct file* fp, char* user_buffer, size_t user_buffer_size, loff_t *offset)
{
	size_t remaining = 8 - *offset;
	size_t copylen = (remaining < user_buffer_size)? remaining : user_buffer_size;
	printk("Read was just called!\n");
	if(*offset == 8)
		return 0;
	strncpy(user_buffer, "buffalo" + *offset, copylen);
	*offset = copylen;
	return copylen;
}

ssize_t demo_write(struct file* fp, const char *user_buffer, size_t user_buffer_size, loff_t *offset)
{
	printk("Write was just called!  User wants to write %s (%lu bytes)\n", user_buffer, user_buffer_size);
	return user_buffer_size;
}

struct file_operations our_file_operations = {
	read: demo_read,
	write:	demo_write
};

int __init init(void)
{
	printk("This is in the kernel!\n");
	proc_create("useproc_demo", 0, 0, &our_file_operations);
	return 0;
}

void __exit cleanup(void)
{	
	remove_proc_entry("useproc_demo", 0);
	printk("We're out of the kernel now\n");
}

module_init(init);
module_exit(cleanup);