LXR busybox/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//config:config RUNLEVEL
  15//config:       bool "runlevel (559 bytes)"
  16//config:       default y
  17//config:       depends on FEATURE_UTMP
  18//config:       help
  19//config:       Find the current and previous system runlevel.
  20//config:
  21//config:       This applet uses utmp but does not rely on busybox supporing
  22//config:       utmp on purpose. It is used by e.g. emdebian via /etc/init.d/rc.
  23
  24//applet:IF_RUNLEVEL(APPLET_NOEXEC(runlevel, runlevel, BB_DIR_SBIN, BB_SUID_DROP, runlevel))
  25
  26//kbuild:lib-$(CONFIG_RUNLEVEL) += runlevel.o
  27
  28//usage:#define runlevel_trivial_usage
  29//usage:       "[FILE]"
  30//usage:#define runlevel_full_usage "\n\n"
  31//usage:       "Find the current and previous system runlevel\n"
  32//usage:       "\n"
  33//usage:       "If no utmp FILE exists or if no runlevel record can be found,\n"
  34//usage:       "print \"unknown\""
  35//usage:
  36//usage:#define runlevel_example_usage
  37//usage:       "$ runlevel /var/run/utmp\n"
  38//usage:       "N 2"
  39
  40#include "libbb.h"
  41
  42int runlevel_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  43int runlevel_main(int argc UNUSED_PARAM, char **argv)
  44{
  45        struct utmpx *ut;
  46        char prev;
  47
  48        if (argv[1]) utmpxname(argv[1]);
  49
  50        setutxent();
  51        while ((ut = getutxent()) != NULL) {
  52                if (ut->ut_type == RUN_LVL) {
  53                        prev = ut->ut_pid / 256;
  54                        if (prev == 0) prev = 'N';
  55                        printf("%c %c\n", prev, ut->ut_pid % 256);
  56                        if (ENABLE_FEATURE_CLEAN_UP)
  57                                endutxent();
  58                        return 0;
  59                }
  60        }
  61
  62        puts("unknown");
  63
  64        if (ENABLE_FEATURE_CLEAN_UP)
  65                endutxent();
  66        return 1;
  67}
  68