src/sleep.c

   1 /* sleep - delay for a specified amount of time.
   2    Copyright (C) 1984-2023 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 <https://www.gnu.org/licenses/>.  */
  16
  17 #include <config.h>
  18 #include <stdio.h>
  19 #include <sys/types.h>
  20
  21 #include "system.h"
  22 #include "cl-strtod.h"
  23 #include "die.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.  NUMBER need not be an\n\
  49 integer.  Given two or more arguments, pause for the amount of time\n\
  50 specified by the sum of their values.\n\
  51 \n\
  52 "),
  53               program_name, program_name);
  54       fputs (HELP_OPTION_DESCRIPTION, stdout);
  55       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  56       emit_ancillary_info (PROGRAM_NAME);
  57     }
  58   exit (status);
  59 }
  60
  61 /* Given a floating point value *X, and a suffix character, SUFFIX_CHAR,
  62    scale *X by the multiplier implied by SUFFIX_CHAR.  SUFFIX_CHAR may
  63    be the NUL byte or 's' to denote seconds, 'm' for minutes, 'h' for
  64    hours, or 'd' for days.  If SUFFIX_CHAR is invalid, don't modify *X
  65    and return false.  Otherwise return true.  */
  66
  67 static bool
  68 apply_suffix (double *x, char suffix_char)
  69 {
  70   int multiplier;
  71
  72   switch (suffix_char)
  73     {
  74     case 0:
  75     case 's':
  76       multiplier = 1;
  77       break;
  78     case 'm':
  79       multiplier = 60;
  80       break;
  81     case 'h':
  82       multiplier = 60 * 60;
  83       break;
  84     case 'd':
  85       multiplier = 60 * 60 * 24;
  86       break;
  87     default:
  88       return false;
  89     }
  90
  91   *x *= multiplier;
  92
  93   return true;
  94 }
  95
  96 int
  97 main (int argc, char **argv)
  98 {
  99   double seconds = 0.0;
 100   bool ok = true;
 101
 102   initialize_main (&argc, &argv);
 103   set_program_name (argv[0]);
 104   setlocale (LC_ALL, "");
 105   bindtextdomain (PACKAGE, LOCALEDIR);
 106   textdomain (PACKAGE);
 107
 108   atexit (close_stdout);
 109
 110   parse_gnu_standard_options_only (argc, argv, PROGRAM_NAME, PACKAGE_NAME,
 111                                    Version, true, usage, AUTHORS,
 112                                    (char const *) NULL);
 113
 114   if (argc == 1)
 115     {
 116       error (0, 0, _("missing operand"));
 117       usage (EXIT_FAILURE);
 118     }
 119
 120   for (int i = optind; i < argc; i++)
 121     {
 122       double s;
 123       char const *p;
 124       if (! (xstrtod (argv[i], &p, &s, cl_strtod) || errno == ERANGE)
 125           /* Nonnegative interval.  */
 126           || ! (0 <= s)
 127           /* No extra chars after the number and an optional s,m,h,d char.  */
 128           || (*p && *(p + 1))
 129           /* Check any suffix char and update S based on the suffix.  */
 130           || ! apply_suffix (&s, *p))
 131         {
 132           error (0, 0, _("invalid time interval %s"), quote (argv[i]));
 133           ok = false;
 134         }
 135
 136       seconds += s;
 137     }
 138
 139   if (!ok)
 140     usage (EXIT_FAILURE);
 141
 142   if (xnanosleep (seconds))
 143     die (EXIT_FAILURE, errno, _("cannot read realtime clock"));
 144
 145   return EXIT_SUCCESS;
 146 }