how can i write into a proc

[a_n_h]

hi there,

i am working on a homework assignment of mine, and i need to write a module that tells us the system time in seconds and microseconds, and i need a lil help, i am stuck in the part where i need to write into a proc file i created, i just dono how to do it, i searched everywhere for a function that may help me but to no avail, anyone here can help me please???

here is my current code

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


#define PROCFS_NAME 	"rexor"

static struct proc_dir_entry *proc_file;



static int __init init(void)
{
	struct timeval time; 


	proc_file = create_proc_entry(PROCFS_NAME, 0, NULL);

	if(proc_file == NULL)
	{
		remove_proc_entry(PROCFS_NAME, NULL);
		printk(KERN_ALERT "Error: Could not initialize /proc/%s\n", 				PROCFS_NAME);

		return -ENOMEM;

	}
       	
     do_gettimeofday(&time);
//     printk(KERN_EMERG "%d.%d", time.tv_sec,time.tv_usec);
	proc_file->write_proc ;


     return 0;
}
static void __exit exit(void)
{
	remove_proc_entry(PROCFS_NAME, NULL);
}
MODULE_LICENSE("GPL");

module_init(init);
module_exit(exit);

using do_gettimeofday i am able to obtain the current time, but i just dono how to write this time into /proc/rexor

thanks in advance

P.S: ITS MY FIRST POST YAYE :P, also i know rexor is a stupid name for a proc dictionary, i will change it later to currentTime or smth.
P.P.S: i dont want to make another post about this, so does anyone here know what callback_read does, cuz i think it may help me out in this problem

[GNU-Fan]

Hello,

this webpage should help you there.
Access the Linux kernel using the /proc filesystem


callback_read is supposed to be a callback function, i.e. it is up to you what is does.
You write this function as you want and it gets called when "something" specific happens.

[a_n_h]

yea thank u but that is not what i ment

i am looking for a function similar to sprintf in C, isnt there a sprintk or smth?

EDIT: nvm i figured it out

[a_n_h]

k i need help, i thought i figured it out, but i didnt

here is my current code

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

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("an LKM that gives the current system time");
MODULE_AUTHOR("sfsdfdsf");


#define PROCFS_NAME 	"currenttime"

struct proc_dir_entry *proc_file;



int init(void)
{
	struct timeval time; 


	proc_file = create_proc_entry(PROCFS_NAME, 0,  NULL);

	if(proc_file == NULL)
	{
		remove_proc_entry(PROCFS_NAME, NULL);
		printk(KERN_ALERT "Error: Could not initialize /proc/%s\n", PROCFS_NAME);

		return -ENOMEM;

	}
       	
	do_gettimeofday(&time);

	
	//sprintf(proc_file,"%d %d\n",time.tv_sec, time.tv_usec);
	



     return 0;
}
void exit(void)
{
	remove_proc_entry(PROCFS_NAME, NULL);
}


module_init(init);
module_exit(exit);

the problem is with sprintf, as i said i want currenttime to hold the current time in seconds and nanoseconds, but i am stuck, anyone could help me please

EDIT: well, it now works yaye

[Rubberman]

You are using sprintf() to output to a structure. This is not valid. You can only sprintf() to a char array (buffer).

[a_n_h]

You are using sprintf() to output to a structure. This is not valid. You can only sprintf() to a char array (buffer).

yea i figured that out, and it works flawlessly (this time for sure :P)

anywayz thank u all for your help