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         fputs(USAGE_HELP, out);
  35         fputs(USAGE_VERSION,out);
  36         fprintf(out, USAGE_MAN_TAIL("ctrlaltdel(8)"));
  37         exit(EXIT_SUCCESS);
  38 }
  39
  40 static int get_cad(void)
  41 {
  42         uint64_t val = path_read_u64(_PATH_PROC_CTRL_ALT_DEL);
  43
  44         switch (val) {
  45         case 0:
  46                 fputs("soft\n", stdout);
  47                 break;
  48         case 1:
  49                 fputs("hard\n", stdout);
  50                 break;
  51         default:
  52                 printf("%s hard\n", _("implicit"));
  53                 warnx(_("unexpected value in %s: %ju"), _PATH_PROC_CTRL_ALT_DEL, val);
  54                 return EXIT_FAILURE;
  55         }
  56         return EXIT_SUCCESS;
  57 }
  58
  59 static int set_cad(const char *arg)
  60 {
  61         unsigned int cmd;
  62
  63         if (geteuid()) {
  64                 warnx(_("You must be root to set the Ctrl-Alt-Del behavior"));
  65                 return EXIT_FAILURE;
  66         }
  67         if (!strcmp("hard", arg))
  68                 cmd = LINUX_REBOOT_CMD_CAD_ON;
  69         else if (!strcmp("soft", arg))
  70                 cmd = LINUX_REBOOT_CMD_CAD_OFF;
  71         else {
  72                 warnx(_("unknown argument: %s"), arg);
  73                 return EXIT_FAILURE;
  74         }
  75         if (reboot(cmd) < 0) {
  76                 warnx("reboot");
  77                 return EXIT_FAILURE;
  78         }
  79         return EXIT_SUCCESS;
  80 }
  81
  82 int main(int argc, char **argv)
  83 {
  84         int ch, ret;
  85         static const struct option longopts[] = {
  86                 {"version", no_argument, NULL, 'V'},
  87                 {"help", no_argument, NULL, 'h'},
  88                 {NULL, 0, NULL, 0}
  89         };
  90
  91         setlocale(LC_ALL, "");
  92         bindtextdomain(PACKAGE, LOCALEDIR);
  93         textdomain(PACKAGE);
  94         atexit(close_stdout);
  95
  96         while ((ch = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1)
  97                 switch (ch) {
  98                 case 'V':
  99                         printf(UTIL_LINUX_VERSION);
 100                         return EXIT_SUCCESS;
 101                 case 'h':
 102                         usage();
 103                 default:
 104                         errtryhelp(EXIT_FAILURE);
 105                 }
 106
 107         if (argc < 2)
 108                 ret = get_cad();
 109         else
 110                 ret = set_cad(argv[1]);
 111         return ret;
 112 }