halt.c

操作系统源代码

/* halt / reboot - halt or reboot system (depends on name)

   halt   - calling reboot() with RBT_HALT
   reboot - calling reboot() with RBT_REBOOT

   author: Edvard Tuinder   [e-mail]

   This program calls the library function reboot(2) which performs
   the system-call do_reboot. 

 */

#define _POSIX_SOURCE	1
#include <sys/types.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>

void write_log _ARGS(( void ));
int main _ARGS(( int argc, char *argv[] ));

char *prog;

int
main(argc,argv)
int argc;
char **argv;
{
  int flag = RBT_HALT;		/* halting system is default */
  int fast = 0;			/* fast halt/reboot, don't kill all. */
  struct stat dummy;

  prog = strrchr(*argv,'/');
  if (prog == (char *)0)
    prog = *argv;
  else
    prog++;

  if (argc > 1) {
    if (strcmp(argv[1], "-f") == 0)
      fast = 1;
    else {
      fprintf(stderr, "Usage: %s [-f]\n", prog);
      exit(1);
    }
  }

  /* Make sure that we don't die. */
  signal(SIGHUP, SIG_IGN);
  signal(SIGTERM, SIG_IGN);

  if (stat("/usr/bin", &dummy) < 0) {
    /* It seems that /usr isn't present, let's assume "-f." */
    fast = 1;
  }

  if (fast) {
    sleep(1);	/* Not too fast, people like to see it "do something". */
  } else {
    /* Tell init to stop spawning getty's. */
    kill(1, SIGTERM);
    /* Give everybody a chance to die peacefully. */
    kill(-1, SIGTERM);
    sleep(2);
  }

  if (strcmp(prog,"reboot"))
    flag=RBT_HALT;
  else
    flag=RBT_REBOOT;
  
  write_log();
  reboot(flag);
  fprintf(stderr, "reboot call failed\n");
  return 1;
}