src/sleep.c

   1 /* sleep - delay for a specified amount of time.
   2    Copyright (C) 1984, 1991-1997, 1999-2005, 2007-2010 Free Software
   3    Foundation, Inc.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation, either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program 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
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19 #include <stdio.h>
  20 #include <sys/types.h>
  21 #include <getopt.h>
  22
  23 #include "system.h"
  24 #include "c-strtod.h"
  25 #include "error.h"
  26 #include "long-options.h"
  27 #include "quote.h"
  28 #include "xnanosleep.h"
  29 #include "xstrtod.h"
  30
  31 /* The official name of this program (e.g., no `g' prefix).  */
  32 #define PROGRAM_NAME "sleep"
  33
  34 #define AUTHORS \
  35   proper_name ("Jim Meyering"), \
  36   proper_name ("Paul Eggert")
  37
  38 void
  39 usage (int status)
  40 {
  41   if (status != EXIT_SUCCESS)
  42     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  43              program_name);
  44   else
  45     {
  46       printf (_("\
  47 Usage: %s NUMBER[SUFFIX]...\n\
  48   or:  %s OPTION\n\
  49 Pause for NUMBER seconds.  SUFFIX may be `s' for seconds (the default),\n\
  50 `m' for minutes, `h' for hours or `d' for days.  Unlike most implementations\n\
  51 that require NUMBER be an integer, here NUMBER may be an arbitrary floating\n\
  52 point number.  Given two or more arguments, pause for the amount of time\n\
  53 specified by the sum of their values.\n\
  54 \n\
  55 "),
  56               program_name, program_name);
  57       fputs (HELP_OPTION_DESCRIPTION, stdout);
  58       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  59       emit_ancillary_info ();
  60     }
  61   exit (status);
  62 }
  63
  64 /* Given a floating point value *X, and a suffix character, SUFFIX_CHAR,
  65    scale *X by the multiplier implied by SUFFIX_CHAR.  SUFFIX_CHAR may
  66    be the NUL byte or `s' to denote seconds, `m' for minutes, `h' for
  67    hours, or `d' for days.  If SUFFIX_CHAR is invalid, don't modify *X
  68    and return false.  Otherwise return true.  */
  69
  70 static bool
  71 apply_suffix (double *x, char suffix_char)
  72 {
  73   int multiplier;
  74
  75   switch (suffix_char)
  76     {
  77     case 0:
  78     case 's':
  79       multiplier = 1;
  80       break;
  81     case 'm':
  82       multiplier = 60;
  83       break;
  84     case 'h':
  85       multiplier = 60 * 60;
  86       break;
  87     case 'd':
  88       multiplier = 60 * 60 * 24;
  89       break;
  90     default:
  91       return false;
  92     }
  93
  94   *x *= multiplier;
  95
  96   return true;
  97 }
  98
  99 int
 100 main (int argc, char **argv)
 101 {
 102   int i;
 103   double seconds = 0.0;
 104   bool ok = true;
 105
 106   initialize_main (&argc, &argv);
 107   set_program_name (argv[0]);
 108   setlocale (LC_ALL, "");
 109   bindtextdomain (PACKAGE, LOCALEDIR);
 110   textdomain (PACKAGE);
 111
 112   atexit (close_stdout);
 113
 114   parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE_NAME, Version,
 115                       usage, AUTHORS, (char const *) NULL);
 116   if (getopt_long (argc, argv, "", NULL, NULL) != -1)
 117     usage (EXIT_FAILURE);
 118
 119   if (argc == 1)
 120     {
 121       error (0, 0, _("missing operand"));
 122       usage (EXIT_FAILURE);
 123     }
 124
 125   for (i = optind; i < argc; i++)
 126     {
 127       double s;
 128       const char *p;
 129       if (! xstrtod (argv[i], &p, &s, c_strtod)
 130           /* Nonnegative interval.  */
 131           || ! (0 <= s)
 132           /* No extra chars after the number and an optional s,m,h,d char.  */
 133           || (*p && *(p+1))
 134           /* Check any suffix char and update S based on the suffix.  */
 135           || ! apply_suffix (&s, *p))
 136         {
 137           error (0, 0, _("invalid time interval %s"), quote (argv[i]));
 138           ok = false;
 139         }
 140
 141       seconds += s;
 142     }
 143
 144   if (!ok)
 145     usage (EXIT_FAILURE);
 146
 147   if (xnanosleep (seconds))
 148     error (EXIT_FAILURE, errno, _("cannot read realtime clock"));
 149
 150   exit (EXIT_SUCCESS);
 151 }