uptime.c

   1 /*
   2  * uptime.c - display system uptime
   3  * Copyright (C) 2012 Craig Small <csmall-procps@enc.com.au>
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19
  20 #include <errno.h>
  21 #include <getopt.h>
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <time.h>
  25 #include <sys/time.h>
  26
  27 #include "c.h"
  28 #include "fileutils.h"
  29 #include "nls.h"
  30 #include "proc/sysinfo.h"
  31 #include "proc/whattime.h"
  32 #include "proc/version.h"
  33
  34 static void print_uptime_since()
  35 {
  36         double now, uptime_secs, idle_secs;
  37         time_t up_since_secs;
  38         struct tm *up_since;
  39         struct timeval tim;
  40
  41         /* Get the current time and convert it to a double */
  42         if (gettimeofday(&tim, NULL) != 0)
  43                 xerr(EXIT_FAILURE, "gettimeofday");
  44         now = tim.tv_sec + (tim.tv_usec / 1000000.0);
  45
  46         /* Get the uptime and calculate when that was */
  47         if (uptime(&uptime_secs, &idle_secs) == 0)
  48                 xerrx(EXIT_FAILURE, "uptime");
  49         up_since_secs = (time_t) ((now - uptime_secs) + 0.5);
  50
  51         /* Show this */
  52         if ((up_since = localtime(&up_since_secs)) == NULL)
  53                 xerrx(EXIT_FAILURE, "localtime");
  54         printf("%04d-%02d-%02d %02d:%02d:%02d\n",
  55                 up_since->tm_year + 1900, up_since->tm_mon + 1, up_since->tm_mday,
  56                 up_since->tm_hour, up_since->tm_min, up_since->tm_sec);
  57 }
  58
  59 static void __attribute__ ((__noreturn__)) usage(FILE * out)
  60 {
  61         fputs(USAGE_HEADER, out);
  62         fprintf(out, _(" %s [options]\n"), program_invocation_short_name);
  63         fputs(USAGE_OPTIONS, out);
  64         fputs(_(" -p, --pretty   show uptime in pretty format\n"), out);
  65         fputs(USAGE_HELP, out);
  66         fputs(_(" -s, --since    system up since\n"), out);
  67         fputs(USAGE_VERSION, out);
  68         fprintf(out, USAGE_MAN_TAIL("uptime(1)"));
  69
  70         exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
  71 }
  72
  73 int main(int argc, char **argv)
  74 {
  75         int c, p = 0;
  76
  77         static const struct option longopts[] = {
  78                 {"pretty", no_argument, NULL, 'p'},
  79                 {"help", no_argument, NULL, 'h'},
  80                 {"since", no_argument, NULL, 's'},
  81                 {"version", no_argument, NULL, 'V'},
  82                 {NULL, 0, NULL, 0}
  83         };
  84
  85 #ifdef HAVE_PROGRAM_INVOCATION_NAME
  86         program_invocation_name = program_invocation_short_name;
  87 #endif
  88         setlocale (LC_ALL, "");
  89         bindtextdomain(PACKAGE, LOCALEDIR);
  90         textdomain(PACKAGE);
  91         atexit(close_stdout);
  92
  93         while ((c = getopt_long(argc, argv, "phsV", longopts, NULL)) != -1)
  94                 switch (c) {
  95                 case 'p':
  96                         p = 1;
  97                         break;
  98                 case 'h':
  99                         usage(stdout);
 100                 case 's':
 101                         print_uptime_since();
 102                         return EXIT_SUCCESS;
 103                 case 'V':
 104                         printf(PROCPS_NG_VERSION);
 105                         return EXIT_SUCCESS;
 106                 default:
 107                         usage(stderr);
 108                 }
 109
 110         print_uptime(p);
 111         return EXIT_SUCCESS;
 112 }