src/sleep.c

   1 /* sleep - delay for a specified amount of time.
   2    Copyright (C) 84, 1991-1997, 1999-2005, 2007 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 #include <config.h>
  18 #include <stdio.h>
  19 #include <sys/types.h>
  20 #include <getopt.h>
  21
  22 #include "system.h"
  23 #include "c-strtod.h"
  24 #include "error.h"
  25 #include "long-options.h"
  26 #include "quote.h"
  27 #include "xnanosleep.h"
  28 #include "xstrtod.h"
  29
  30 /* The official name of this program (e.g., no `g' prefix).  */
  31 #define PROGRAM_NAME "sleep"
  32
  33 #define AUTHORS \
  34   proper_name ("Jim Meyering"), \
  35   proper_name ("Paul Eggert")
  36
  37 /* The name by which this program was run. */
  38 char *program_name;
  39
  40 void
  41 usage (int status)
  42 {
  43   if (status != EXIT_SUCCESS)
  44     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  45              program_name);
  46   else
  47     {
  48       printf (_("\
  49 Usage: %s NUMBER[SUFFIX]...\n\
  50   or:  %s OPTION\n\
  51 Pause for NUMBER seconds.  SUFFIX may be `s' for seconds (the default),\n\
  52 `m' for minutes, `h' for hours or `d' for days.  Unlike most implementations\n\
  53 that require NUMBER be an integer, here NUMBER may be an arbitrary floating\n\
  54 point number.  Given two or more arguments, pause for the amount of time\n\
  55 specified by the sum of their values.\n\
  56 \n\
  57 "),
  58               program_name, program_name);
  59       fputs (HELP_OPTION_DESCRIPTION, stdout);
  60       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  61       emit_bug_reporting_address ();
  62     }
  63   exit (status);
  64 }
  65
  66 /* Given a floating point value *X, and a suffix character, SUFFIX_CHAR,
  67    scale *X by the multiplier implied by SUFFIX_CHAR.  SUFFIX_CHAR may
  68    be the NUL byte or `s' to denote seconds, `m' for minutes, `h' for
  69    hours, or `d' for days.  If SUFFIX_CHAR is invalid, don't modify *X
  70    and return false.  Otherwise return true.  */
  71
  72 static bool
  73 apply_suffix (double *x, char suffix_char)
  74 {
  75   int multiplier;
  76
  77   switch (suffix_char)
  78     {
  79     case 0:
  80     case 's':
  81       multiplier = 1;
  82       break;
  83     case 'm':
  84       multiplier = 60;
  85       break;
  86     case 'h':
  87       multiplier = 60 * 60;
  88       break;
  89     case 'd':
  90       multiplier = 60 * 60 * 24;
  91       break;
  92     default:
  93       return false;
  94     }
  95
  96   *x *= multiplier;
  97
  98   return true;
  99 }
 100
 101 int
 102 main (int argc, char **argv)
 103 {
 104   int i;
 105   double seconds = 0.0;
 106   bool ok = true;
 107
 108   initialize_main (&argc, &argv);
 109   program_name = argv[0];
 110   setlocale (LC_ALL, "");
 111   bindtextdomain (PACKAGE, LOCALEDIR);
 112   textdomain (PACKAGE);
 113
 114   atexit (close_stdout);
 115
 116   parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE_NAME, VERSION,
 117                       usage, AUTHORS, (char const *) NULL);
 118   if (getopt_long (argc, argv, "", NULL, NULL) != -1)
 119     usage (EXIT_FAILURE);
 120
 121   if (argc == 1)
 122     {
 123       error (0, 0, _("missing operand"));
 124       usage (EXIT_FAILURE);
 125     }
 126
 127   for (i = optind; i < argc; i++)
 128     {
 129       double s;
 130       const char *p;
 131       if (! xstrtod (argv[i], &p, &s, c_strtod)
 132           /* Nonnegative interval.  */
 133           || ! (0 <= s)
 134           /* No extra chars after the number and an optional s,m,h,d char.  */
 135           || (*p && *(p+1))
 136           /* Check any suffix char and update S based on the suffix.  */
 137           || ! apply_suffix (&s, *p))
 138         {
 139           error (0, 0, _("invalid time interval %s"), quote (argv[i]));
 140           ok = false;
 141         }
 142
 143       seconds += s;
 144     }
 145
 146   if (!ok)
 147     usage (EXIT_FAILURE);
 148
 149   if (xnanosleep (seconds))
 150     error (EXIT_FAILURE, errno, _("cannot read realtime clock"));
 151
 152   exit (EXIT_SUCCESS);
 153 }