sys-utils/ctrlaltdel.c

   1 /*
   2  * SPDX-License-Identifier: GPL-2.0-or-later
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * Copyright (C) 1992 Peter Orbaek <poe@daimi.aau.dk>
  10  * Copyright (C) 1992-1993 Rickard E. Faith <faith@cs.unc.edu>
  11  *
  12  * Set the function of the Ctrl-Alt-Del combination
  13  */
  14 #include <getopt.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <errno.h>
  19 #include <unistd.h>
  20 #include <sys/reboot.h>
  21 #include "nls.h"
  22 #include "c.h"
  23 #include "closestream.h"
  24 #include "pathnames.h"
  25 #include "path.h"
  26
  27 #define LINUX_REBOOT_CMD_CAD_ON 0x89ABCDEF
  28 #define LINUX_REBOOT_CMD_CAD_OFF 0x00000000
  29
  30 static void __attribute__((__noreturn__)) usage(void)
  31 {
  32         FILE *out = stdout;
  33         fputs(USAGE_HEADER, out);
  34         fprintf(out, _(" %s hard|soft\n"), program_invocation_short_name);
  35
  36         fputs(USAGE_SEPARATOR, out);
  37         fprintf(out, _("Set the function of the Ctrl-Alt-Del combination.\n"));
  38
  39         fputs(USAGE_OPTIONS, out);
  40         fprintf(out, USAGE_HELP_OPTIONS(16));
  41         fprintf(out, USAGE_MAN_TAIL("ctrlaltdel(8)"));
  42         exit(EXIT_SUCCESS);
  43 }
  44
  45 static int get_cad(void)
  46 {
  47         uint64_t val;
  48
  49         if (ul_path_read_u64(NULL, &val, _PATH_PROC_CTRL_ALT_DEL) != 0)
  50                 err(EXIT_FAILURE, _("cannot read %s"), _PATH_PROC_CTRL_ALT_DEL);
  51
  52         switch (val) {
  53         case 0:
  54                 fputs("soft\n", stdout);
  55                 break;
  56         case 1:
  57                 fputs("hard\n", stdout);
  58                 break;
  59         default:
  60                 printf("%s hard\n", _("implicit"));
  61                 warnx(_("unexpected value in %s: %ju"), _PATH_PROC_CTRL_ALT_DEL, val);
  62                 return EXIT_FAILURE;
  63         }
  64         return EXIT_SUCCESS;
  65 }
  66
  67 static int set_cad(const char *arg)
  68 {
  69         unsigned int cmd;
  70
  71         if (!strcmp("hard", arg))
  72                 cmd = LINUX_REBOOT_CMD_CAD_ON;
  73         else if (!strcmp("soft", arg))
  74                 cmd = LINUX_REBOOT_CMD_CAD_OFF;
  75         else {
  76                 warnx(_("unknown argument: %s"), arg);
  77                 return EXIT_FAILURE;
  78         }
  79         if (reboot(cmd) < 0) {
  80                 warn("reboot");
  81                 return EXIT_FAILURE;
  82         }
  83         return EXIT_SUCCESS;
  84 }
  85
  86 int main(int argc, char **argv)
  87 {
  88         int ch, ret;
  89         static const struct option longopts[] = {
  90                 {"version", no_argument, NULL, 'V'},
  91                 {"help", no_argument, NULL, 'h'},
  92                 {NULL, 0, NULL, 0}
  93         };
  94
  95         setlocale(LC_ALL, "");
  96         bindtextdomain(PACKAGE, LOCALEDIR);
  97         textdomain(PACKAGE);
  98         close_stdout_atexit();
  99
 100         while ((ch = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1)
 101                 switch (ch) {
 102                 case 'V':
 103                         print_version(EXIT_SUCCESS);
 104                 case 'h':
 105                         usage();
 106                 default:
 107                         errtryhelp(EXIT_FAILURE);
 108                 }
 109
 110         if (argc < 2)
 111                 ret = get_cad();
 112         else
 113                 ret = set_cad(argv[1]);
 114         return ret;
 115 }