console-tools/kbd_mode.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini kbd_mode implementation for busybox
   4  *
   5  * Copyright (C) 2007 Loic Grenie <loic.grenie@gmail.com>
   6  *   written using Andries Brouwer <aeb@cwi.nl>'s kbd_mode from
   7  *   console-utils v0.2.3, licensed under GNU GPLv2
   8  *
   9  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  10  */
  11 //config:config KBD_MODE
  12 //config:       bool "kbd_mode (4.3 kb)"
  13 //config:       default y
  14 //config:       help
  15 //config:       This program reports and sets keyboard mode.
  16
  17 //applet:IF_KBD_MODE(APPLET_NOEXEC(kbd_mode, kbd_mode, BB_DIR_BIN, BB_SUID_DROP, kbd_mode))
  18
  19 //kbuild:lib-$(CONFIG_KBD_MODE) += kbd_mode.o
  20
  21 //usage:#define kbd_mode_trivial_usage
  22 //usage:       "[-a|k|s|u] [-C TTY]"
  23 //usage:#define kbd_mode_full_usage "\n\n"
  24 //usage:       "Report or set VT console keyboard mode\n"
  25 //usage:     "\n        -a      Default (ASCII)"
  26 //usage:     "\n        -k      Medium-raw (keycode)"
  27 //usage:     "\n        -s      Raw (scancode)"
  28 //usage:     "\n        -u      Unicode (utf-8)"
  29 //usage:     "\n        -C TTY  Affect TTY"
  30
  31 #include "libbb.h"
  32 #include <linux/kd.h>
  33
  34 int kbd_mode_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  35 int kbd_mode_main(int argc UNUSED_PARAM, char **argv)
  36 {
  37         enum {
  38                 SCANCODE  = (1 << 0),
  39                 ASCII     = (1 << 1),
  40                 MEDIUMRAW = (1 << 2),
  41                 UNICODE   = (1 << 3),
  42         };
  43         int fd;
  44         unsigned opt;
  45         const char *tty_name;
  46
  47         opt = getopt32(argv, "sakuC:", &tty_name);
  48         if (opt & 0x10) {
  49                 opt &= 0xf; /* clear -C bit, see (*) */
  50                 fd = xopen_nonblocking(tty_name);
  51         } else {
  52                 /* kbd-2.0.3 tries in sequence:
  53                  * fd#0, /dev/tty, /dev/tty0.
  54                  * get_console_fd_or_die: /dev/console, /dev/tty0, /dev/tty.
  55                  * kbd-2.0.3 checks KDGKBTYPE, get_console_fd_or_die checks too.
  56                  */
  57                 fd = get_console_fd_or_die();
  58         }
  59
  60         if (!opt) { /* print current setting */
  61                 const char *mode = "unknown";
  62                 int m;
  63
  64                 xioctl(fd, KDGKBMODE, &m);
  65                 if (m == K_RAW)
  66                         mode = "raw (scancode)";
  67                 else if (m == K_XLATE)
  68                         mode = "default (ASCII)";
  69                 else if (m == K_MEDIUMRAW)
  70                         mode = "mediumraw (keycode)";
  71                 else if (m == K_UNICODE)
  72                         mode = "Unicode (UTF-8)";
  73                 else if (m == 4 /*K_OFF*/) /* kbd-2.0.3 does not show this mode, says "unknown" */
  74                         mode = "off";
  75                 printf("The keyboard is in %s mode\n", mode);
  76         } else {
  77                 /* here we depend on specific bits assigned to options (*)
  78                  * KDSKBMODE constants have these values:
  79                  * #define K_RAW           0x00
  80                  * #define K_XLATE         0x01
  81                  * #define K_MEDIUMRAW     0x02
  82                  * #define K_UNICODE       0x03
  83                  * #define K_OFF           0x04
  84                  * (looks like "-ak" together would cause the same effect as -u)
  85                  */
  86                 opt = opt & UNICODE ? 3 : opt >> 1;
  87                 /* double cast prevents warnings about widening conversion */
  88                 xioctl(fd, KDSKBMODE, (void*)(ptrdiff_t)opt);
  89         }
  90
  91         if (ENABLE_FEATURE_CLEAN_UP)
  92                 close(fd);
  93         return EXIT_SUCCESS;
  94 }