BSD 4 release

[unix-history] / usr / src / cmd / halt.c

static  char *sccsid = "@(#)halt.c      4.2 (Berkeley) 11/10/80";
/*
* Halt
*/
#include <stdio.h>
#include <sys/reboot.h>

main(argc, argv)
       int argc;
       char **argv;
{
       int howto;
       char *ttyn = (char *)ttyname(2);

       howto = RB_HALT;
       argc--, argv++;
       while (argc > 0) {
               if (!strcmp(*argv, "-n"))
                       howto |= RB_NOSYNC;
               else if (!strcmp(*argv, "-y"))
                       ttyn = 0;
               else {
                       fprintf(stderr, "usage: halt [ -n ]\n");
                       exit(1);
               }
               argc--, argv++;
       }
       if (ttyn && *(ttyn+strlen("/dev/tty")) == 'd') {
               fprintf(stderr, "halt: dangerous on a dialup; use ``halt -y'' if you are really sure\n");
               exit(1);
       }
       syscall(55, howto);
       perror("reboot");
}