sys-utils/ctrlaltdel.c

   1 /*
   2  * ctrlaltdel.c - Set the function of the Ctrl-Alt-Del combination
   3  * Created 4-Jul-92 by Peter Orbaek <poe@daimi.aau.dk>
   4  * 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL>
   5  * - added Native Language Support
   6  */
   7
   8 #include <getopt.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <errno.h>
  13 #include <unistd.h>
  14 #include <sys/reboot.h>
  15 #include "nls.h"
  16 #include "c.h"
  17 #include "closestream.h"
  18 #include "pathnames.h"
  19 #include "path.h"
  20
  21 #define LINUX_REBOOT_CMD_CAD_ON 0x89ABCDEF
  22 #define LINUX_REBOOT_CMD_CAD_OFF 0x00000000
  23
  24 static void __attribute__((__noreturn__)) usage(void)
  25 {
  26         FILE *out = stdout;
  27         fputs(USAGE_HEADER, out);
  28         fprintf(out, _(" %s hard|soft\n"), program_invocation_short_name);
  29
  30         fputs(USAGE_SEPARATOR, out);
  31         fprintf(out, _("Set the function of the Ctrl-Alt-Del combination.\n"));
  32
  33         fputs(USAGE_OPTIONS, out);
  34         printf(USAGE_HELP_OPTIONS(16));
  35         printf(USAGE_MAN_TAIL("ctrlaltdel(8)"));
  36         exit(EXIT_SUCCESS);
  37 }
  38
  39 static int get_cad(void)
  40 {
  41         uint64_t val;
  42
  43         if (ul_path_read_u64(NULL, &val, _PATH_PROC_CTRL_ALT_DEL) != 0)
  44                 err(EXIT_FAILURE, _("cannot read %s"), _PATH_PROC_CTRL_ALT_DEL);
  45
  46         switch (val) {
  47         case 0:
  48                 fputs("soft\n", stdout);
  49                 break;
  50         case 1:
  51                 fputs("hard\n", stdout);
  52                 break;
  53         default:
  54                 printf("%s hard\n", _("implicit"));
  55                 warnx(_("unexpected value in %s: %ju"), _PATH_PROC_CTRL_ALT_DEL, val);
  56                 return EXIT_FAILURE;
  57         }
  58         return EXIT_SUCCESS;
  59 }
  60
  61 static int set_cad(const char *arg)
  62 {
  63         unsigned int cmd;
  64
  65         if (geteuid()) {
  66                 warnx(_("You must be root to set the Ctrl-Alt-Del behavior"));
  67                 return EXIT_FAILURE;
  68         }
  69         if (!strcmp("hard", arg))
  70                 cmd = LINUX_REBOOT_CMD_CAD_ON;
  71         else if (!strcmp("soft", arg))
  72                 cmd = LINUX_REBOOT_CMD_CAD_OFF;
  73         else {
  74                 warnx(_("unknown argument: %s"), arg);
  75                 return EXIT_FAILURE;
  76         }
  77         if (reboot(cmd) < 0) {
  78                 warnx("reboot");
  79                 return EXIT_FAILURE;
  80         }
  81         return EXIT_SUCCESS;
  82 }
  83
  84 int main(int argc, char **argv)
  85 {
  86         int ch, ret;
  87         static const struct option longopts[] = {
  88                 {"version", no_argument, NULL, 'V'},
  89                 {"help", no_argument, NULL, 'h'},
  90                 {NULL, 0, NULL, 0}
  91         };
  92
  93         setlocale(LC_ALL, "");
  94         bindtextdomain(PACKAGE, LOCALEDIR);
  95         textdomain(PACKAGE);
  96         close_stdout_atexit();
  97
  98         while ((ch = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1)
  99                 switch (ch) {
 100                 case 'V':
 101                         print_version(EXIT_SUCCESS);
 102                 case 'h':
 103                         usage();
 104                 default:
 105                         errtryhelp(EXIT_FAILURE);
 106                 }
 107
 108         if (argc < 2)
 109                 ret = get_cad();
 110         else
 111                 ret = set_cad(argv[1]);
 112         return ret;
 113 }