Contorlling to call of "/dev/console" - linux

/*
* ID: console.c
* DESCRIBE: Contorlling to call of "/dev/console",that is speaker of computer's board.
* Author: shengguai168@yahoo.com.cn
* DATE: Mon Nov 12 18:30:24 CST 2007
*/

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <linux/kd.h>

int console_fd;
int i;
int j=100000;

int main (int argc, char **argv)
{
if ((console_fd = open ("/dev/console", O_WRONLY)) == -1)
    {
      printf ("Failed to open console.\n");
      exit (1);
    }
for (i = 0; i < 10; i++)
    {
      ioctl (console_fd, KDMKTONE, (2000 | (300 << 16))); /* setting*/
      ioctl (console_fd, KIOCSOUND, 500); /* tone begining*/
      usleep (j); /*delay*/
      ioctl (console_fd, KIOCSOUND, 0);   /* stop tone*/
      usleep (j); /* delay*/
    }   /* repeat play*/
return 0;
}