LXR busybox/console-tools/deallocvt.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * Disallocate virtual terminal(s)
   4 *
   5 * Copyright (C) 2003 by Tito Ragusa <farmatito@tiscali.it>
   6 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   7 *
   8 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   9 */
  10//config:config DEALLOCVT
  11//config:       bool "deallocvt (1.9 kb)"
  12//config:       default y
  13//config:       select PLATFORM_LINUX
  14//config:       help
  15//config:       This program deallocates unused virtual consoles.
  16
  17//applet:IF_DEALLOCVT(APPLET_NOEXEC(deallocvt, deallocvt, BB_DIR_USR_BIN, BB_SUID_DROP, deallocvt))
  18
  19//kbuild:lib-$(CONFIG_DEALLOCVT) += deallocvt.o
  20
  21//usage:#define deallocvt_trivial_usage
  22//usage:       "[N]"
  23//usage:#define deallocvt_full_usage "\n\n"
  24//usage:       "Deallocate unused virtual terminal /dev/ttyN"
  25
  26#include "libbb.h"
  27
  28/* From <linux/vt.h> */
  29enum { VT_DISALLOCATE = 0x5608 }; /* free memory associated to vt */
  30
  31int deallocvt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  32int deallocvt_main(int argc UNUSED_PARAM, char **argv)
  33{
  34        /* num = 0 deallocate all unused consoles */
  35        int num = 0;
  36
  37        if (argv[1]) {
  38                if (argv[2])
  39                        bb_show_usage();
  40                num = xatou_range(argv[1], 1, 63);
  41        }
  42
  43        /* double cast suppresses "cast to ptr from int of different size" */
  44        xioctl(get_console_fd_or_die(), VT_DISALLOCATE, (void *)(ptrdiff_t)num);
  45        return EXIT_SUCCESS;
  46}
  47