toys/other/chvt.c

/* chvt.c - switch virtual terminals
 *
 * Copyright (C) 2008 David Anders <danders@amltd.com>

USE_CHVT(NEWTOY(chvt, "<1", TOYFLAG_USR|TOYFLAG_SBIN))

config CHVT
  bool "chvt"
  default y
  help
    usage: chvt N

    Change to virtual terminal number N. (This only works in text mode.)

    Virtual terminals are the Linux VGA text mode displays, ordinarily
    switched between via alt-F1, alt-F2, etc. Use ctrl-alt-F1 to switch
    from X to a virtual terminal, and alt-F6 (or F7, or F8) to get back.
*/

#include "toys.h"

/* Note: get_console_fb() will need to be moved into a seperate lib section */
int get_console_fd()
{
  int fd;
  char *consoles[]={"/dev/console", "/dev/vc/0", "/dev/tty", NULL}, **cc;

  cc = consoles;
  while (*cc) {
    fd = open(*cc++, O_RDWR);
    if (fd >= 0) return fd;
  }

  return -1;
}

void chvt_main(void)
{
  int vtnum, fd;

  vtnum=atoi(*toys.optargs);

  fd=get_console_fd();
  // These numbers are VT_ACTIVATE and VT_WAITACTIVE from linux/vt.h
  if (fd < 0 || ioctl(fd, 0x5606, vtnum) || ioctl(fd, 0x5607, vtnum))
    perror_exit(NULL);
}