Example:
	#include <stdio.h>
	#include <fcntl.h>
	#include <unistd.h>
	#include <sys/stat.h>
	#include <linux/vt.h>
	#include <sys/types.h>
	#include <sys/ioctl.h>

	#define ERROR -1

 	void main()
	{
          int fd;
          int tty;

	  printf("w00w00!\n\n");

          if (argc < 2) {
	     printf("Usage: %s <tty>\n", argv[0]);
             printf("tty is a tty to disallocate\n\n");
	     exit(ERROR);
	  }

          tty = atoi(argv[1]);

          /* used as fd for ioctl() */
          if ((fd = open("/dev/tty", O_NOCTTY)) == ERROR) {
	        perror("open");
	        exit(ERROR);
          }

          printf("disallocating tty%d\n", tty);
          if (ioctl(fd, VT_DISALLOCATE, tty) == ERROR) {
             perror("ioctl");
             close(fd);
             exit(ERROR);
          }

          close(fd);
        }