commands/reboot/halt.c

   1 /* halt / reboot - halt or reboot system (depends on name)
   2
   3    halt   - calling reboot() with RBT_HALT
   4    reboot - calling reboot() with RBT_REBOOT
   5
   6    author: Edvard Tuinder   v892231@si.hhs.NL
   7
   8    This program calls the library function reboot(2) which performs
   9    the system-call do_reboot.
  10
  11  */
  12
  13 #define _POSIX_SOURCE   1
  14 #include <sys/types.h>
  15 #include <fcntl.h>
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <signal.h>
  19 #include <string.h>
  20 #include <errno.h>
  21 #include <unistd.h>
  22 #include <sys/stat.h>
  23 #include <sys/wait.h>
  24
  25 #include "wtmp.h"
  26
  27 void write_log( char *fn );
  28 void usage( void );
  29 int main( int argc, char *argv[] );
  30
  31 char *prog;
  32
  33 void
  34 usage()
  35 {
  36   fprintf(stderr, "Usage: %s [-hrRfpd]\n", prog);
  37   exit(1);
  38 }
  39
  40 int
  41 main(argc,argv)
  42 int argc;
  43 char **argv;
  44 {
  45   int flag = -1;                /* default action unknown */
  46   int fast = 0;                 /* fast halt/reboot, don't bother being nice. */
  47   int i;
  48   struct stat dummy;
  49   pid_t pid;
  50
  51   if ((prog = strrchr(argv[0],'/')) == NULL) prog = argv[0]; else prog++;
  52
  53   if (strcmp(prog, "halt") == 0) flag = RBT_HALT;
  54   if (strcmp(prog, "reboot") == 0) flag = RBT_REBOOT;
  55
  56   i = 1;
  57   while (i < argc && argv[i][0] == '-') {
  58     char *opt = argv[i++] + 1;
  59
  60     if (*opt == '-' && opt[1] == 0) break;      /* -- */
  61
  62     while (*opt != 0) switch (*opt++) {
  63       case 'h': flag = RBT_HALT;        break;
  64       case 'r': flag = RBT_REBOOT;      break;
  65       case 'R': flag = RBT_RESET;       break;
  66       case 'd': flag = RBT_DEFAULT;     break;
  67       case 'p': flag = RBT_POWEROFF;    break;
  68       case 'f': fast = 1; break;
  69       default:
  70         usage();
  71     }
  72   }
  73
  74   if (i != argc) usage();
  75
  76   if (flag == -1) {
  77     fprintf(stderr, "Don't know what to do when named '%s'\n", prog);
  78     exit(1);
  79   }
  80
  81   if (stat("/usr/bin", &dummy) < 0) {
  82     /* It seems that /usr isn't present, let's assume "-f." */
  83     fast = 1;
  84   }
  85
  86   signal(SIGHUP, SIG_IGN);
  87   signal(SIGTERM, SIG_IGN);
  88
  89   /* Skip this part for fast shut down. */
  90   if (! fast) {
  91     /* Run the shutdown scripts. */
  92     switch ((pid = fork())) {
  93       case -1:
  94         fprintf(stderr, "%s: can't fork(): %s\n", prog, strerror(errno));
  95         exit(1);
  96       case 0:
  97         execl("/bin/sh", "sh", "/etc/rc", "down", (char *) NULL);
  98         fprintf(stderr, "%s: can't execute: /bin/sh: %s\n",
  99           prog, strerror(errno));
 100         exit(1);
 101       default:
 102         while (waitpid(pid, NULL, 0) != pid) {}
 103     }
 104   }
 105
 106   /* Tell init to stop spawning getty's. */
 107   kill(1, SIGTERM);
 108
 109   /* Extra sync for the case where SIGTERM causes deadlock */
 110   sync();
 111
 112   /* Give everybody a chance to die peacefully. */
 113   printf("Sending SIGTERM to all processes ...\n");
 114   kill(-1, SIGTERM);
 115   sleep(1);
 116
 117   write_log(STR_WTMP);
 118   write_log(STR_ROOT_WTMP);
 119
 120   sync();
 121
 122   reboot(flag);
 123   fprintf(stderr, "%s: reboot(): %s\n", prog, strerror(errno));
 124   return 1;
 125 }