LXR busybox/console-tools/fgconsole.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * Mini fgconsole implementation for busybox
   4 *
   5 * Copyright (C) 2010 by Grigory Batalov <bga@altlinux.org>
   6 *
   7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8 */
   9//config:config FGCONSOLE
  10//config:       bool "fgconsole (1.5 kb)"
  11//config:       default y
  12//config:       help
  13//config:       This program prints active (foreground) console number.
  14
  15//applet:IF_FGCONSOLE(APPLET_NOEXEC(fgconsole, fgconsole, BB_DIR_USR_BIN, BB_SUID_DROP, fgconsole))
  16
  17//kbuild:lib-$(CONFIG_FGCONSOLE) += fgconsole.o
  18
  19//usage:#define fgconsole_trivial_usage
  20//usage:        ""
  21//usage:#define fgconsole_full_usage "\n\n"
  22//usage:        "Get active console"
  23
  24#include "libbb.h"
  25
  26/* From <linux/vt.h> */
  27struct vt_stat {
  28        unsigned short v_active;        /* active vt */
  29        unsigned short v_signal;        /* signal to send */
  30        unsigned short v_state;         /* vt bitmask */
  31};
  32enum { VT_GETSTATE = 0x5603 }; /* get global vt state info */
  33
  34int fgconsole_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  35int fgconsole_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
  36{
  37        struct vt_stat vtstat;
  38
  39        vtstat.v_active = 0;
  40        xioctl(get_console_fd_or_die(), VT_GETSTATE, &vtstat);
  41        printf("%d\n", vtstat.v_active);
  42
  43        return EXIT_SUCCESS;
  44}
  45