src/sleep.c

   1 /* sleep - delay for a specified amount of time.
   2    Copyright (C) 1984-2016 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 void
  38 usage (int status)
  39 {
  40   if (status != EXIT_SUCCESS)
  41     emit_try_help ();
  42   else
  43     {
  44       printf (_("\
  45 Usage: %s NUMBER[SUFFIX]...\n\
  46   or:  %s OPTION\n\
  47 Pause for NUMBER seconds.  SUFFIX may be 's' for seconds (the default),\n\
  48 'm' for minutes, 'h' for hours or 'd' for days.  Unlike most implementations\n\
  49 that require NUMBER be an integer, here NUMBER may be an arbitrary floating\n\
  50 point number.  Given two or more arguments, pause for the amount of time\n\
  51 specified by the sum of their values.\n\
  52 \n\
  53 "),
  54               program_name, program_name);
  55       fputs (HELP_OPTION_DESCRIPTION, stdout);
  56       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  57       emit_ancillary_info (PROGRAM_NAME);
  58     }
  59   exit (status);
  60 }
  61
  62 /* Given a floating point value *X, and a suffix character, SUFFIX_CHAR,
  63    scale *X by the multiplier implied by SUFFIX_CHAR.  SUFFIX_CHAR may
  64    be the NUL byte or 's' to denote seconds, 'm' for minutes, 'h' for
  65    hours, or 'd' for days.  If SUFFIX_CHAR is invalid, don't modify *X
  66    and return false.  Otherwise return true.  */
  67
  68 static bool
  69 apply_suffix (double *x, char suffix_char)
  70 {
  71   int multiplier;
  72
  73   switch (suffix_char)
  74     {
  75     case 0:
  76     case 's':
  77       multiplier = 1;
  78       break;
  79     case 'm':
  80       multiplier = 60;
  81       break;
  82     case 'h':
  83       multiplier = 60 * 60;
  84       break;
  85     case 'd':
  86       multiplier = 60 * 60 * 24;
  87       break;
  88     default:
  89       return false;
  90     }
  91
  92   *x *= multiplier;
  93
  94   return true;
  95 }
  96
  97 int
  98 main (int argc, char **argv)
  99 {
 100   int i;
 101   double seconds = 0.0;
 102   bool ok = true;
 103
 104   initialize_main (&argc, &argv);
 105   set_program_name (argv[0]);
 106   setlocale (LC_ALL, "");
 107   bindtextdomain (PACKAGE, LOCALEDIR);
 108   textdomain (PACKAGE);
 109
 110   atexit (close_stdout);
 111
 112   parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE_NAME, Version,
 113                       usage, AUTHORS, (char const *) NULL);
 114   if (getopt_long (argc, argv, "", NULL, NULL) != -1)
 115     usage (EXIT_FAILURE);
 116
 117   if (argc == 1)
 118     {
 119       error (0, 0, _("missing operand"));
 120       usage (EXIT_FAILURE);
 121     }
 122
 123   for (i = optind; i < argc; i++)
 124     {
 125       double s;
 126       const char *p;
 127       if (! xstrtod (argv[i], &p, &s, c_strtod)
 128           /* Nonnegative interval.  */
 129           || ! (0 <= s)
 130           /* No extra chars after the number and an optional s,m,h,d char.  */
 131           || (*p && *(p+1))
 132           /* Check any suffix char and update S based on the suffix.  */
 133           || ! apply_suffix (&s, *p))
 134         {
 135           error (0, 0, _("invalid time interval %s"), quote (argv[i]));
 136           ok = false;
 137         }
 138
 139       seconds += s;
 140     }
 141
 142   if (!ok)
 143     usage (EXIT_FAILURE);
 144
 145   if (xnanosleep (seconds))
 146     error (EXIT_FAILURE, errno, _("cannot read realtime clock"));
 147
 148   return EXIT_SUCCESS;
 149 }