miscutils/runlevel.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Prints out the previous and the current runlevel.
   4  *
   5  * Version: @(#)runlevel  1.20  16-Apr-1997  MvS
   6  *
   7  * This file is part of the sysvinit suite,
   8  * Copyright 1991-1997 Miquel van Smoorenburg.
   9  *
  10  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  11  *
  12  * initially busyboxified by Bernhard Reutner-Fischer
  13  */
  14
  15 //usage:#define runlevel_trivial_usage
  16 //usage:       "[FILE]"
  17 //usage:#define runlevel_full_usage "\n\n"
  18 //usage:       "Find the current and previous system runlevel\n"
  19 //usage:       "\n"
  20 //usage:       "If no utmp FILE exists or if no runlevel record can be found,\n"
  21 //usage:       "print \"unknown\""
  22 //usage:
  23 //usage:#define runlevel_example_usage
  24 //usage:       "$ runlevel /var/run/utmp\n"
  25 //usage:       "N 2"
  26
  27 #include "libbb.h"
  28
  29 int runlevel_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  30 int runlevel_main(int argc UNUSED_PARAM, char **argv)
  31 {
  32         struct utmp *ut;
  33         char prev;
  34
  35         if (argv[1]) utmpname(argv[1]);
  36
  37         setutent();
  38         while ((ut = getutent()) != NULL) {
  39                 if (ut->ut_type == RUN_LVL) {
  40                         prev = ut->ut_pid / 256;
  41                         if (prev == 0) prev = 'N';
  42                         printf("%c %c\n", prev, ut->ut_pid % 256);
  43                         if (ENABLE_FEATURE_CLEAN_UP)
  44                                 endutent();
  45                         return 0;
  46                 }
  47         }
  48
  49         puts("unknown");
  50
  51         if (ENABLE_FEATURE_CLEAN_UP)
  52                 endutent();
  53         return 1;
  54 }