src/sleep.c

   1 /* sleep - delay for a specified amount of time.
   2    Copyright (C) 1984, 1991-1997, 1999-2005, 2007-2012 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     emit_try_help ();
  43   else
  44     {
  45       printf (_("\
  46 Usage: %s NUMBER[SUFFIX]...\n\
  47   or:  %s OPTION\n\
  48 Pause for NUMBER seconds.  SUFFIX may be 's' for seconds (the default),\n\
  49 'm' for minutes, 'h' for hours or 'd' for days.  Unlike most implementations\n\
  50 that require NUMBER be an integer, here NUMBER may be an arbitrary floating\n\
  51 point number.  Given two or more arguments, pause for the amount of time\n\
  52 specified by the sum of their values.\n\
  53 \n\
  54 "),
  55               program_name, program_name);
  56       fputs (HELP_OPTION_DESCRIPTION, stdout);
  57       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  58       emit_ancillary_info ();
  59     }
  60   exit (status);
  61 }
  62
  63 /* Given a floating point value *X, and a suffix character, SUFFIX_CHAR,
  64    scale *X by the multiplier implied by SUFFIX_CHAR.  SUFFIX_CHAR may
  65    be the NUL byte or 's' to denote seconds, 'm' for minutes, 'h' for
  66    hours, or 'd' for days.  If SUFFIX_CHAR is invalid, don't modify *X
  67    and return false.  Otherwise return true.  */
  68
  69 static bool
  70 apply_suffix (double *x, char suffix_char)
  71 {
  72   int multiplier;
  73
  74   switch (suffix_char)
  75     {
  76     case 0:
  77     case 's':
  78       multiplier = 1;
  79       break;
  80     case 'm':
  81       multiplier = 60;
  82       break;
  83     case 'h':
  84       multiplier = 60 * 60;
  85       break;
  86     case 'd':
  87       multiplier = 60 * 60 * 24;
  88       break;
  89     default:
  90       return false;
  91     }
  92
  93   *x *= multiplier;
  94
  95   return true;
  96 }
  97
  98 int
  99 main (int argc, char **argv)
 100 {
 101   int i;
 102   double seconds = 0.0;
 103   bool ok = true;
 104
 105   initialize_main (&argc, &argv);
 106   set_program_name (argv[0]);
 107   setlocale (LC_ALL, "");
 108   bindtextdomain (PACKAGE, LOCALEDIR);
 109   textdomain (PACKAGE);
 110
 111   atexit (close_stdout);
 112
 113   parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE_NAME, Version,
 114                       usage, AUTHORS, (char const *) NULL);
 115   if (getopt_long (argc, argv, "", NULL, NULL) != -1)
 116     usage (EXIT_FAILURE);
 117
 118   if (argc == 1)
 119     {
 120       error (0, 0, _("missing operand"));
 121       usage (EXIT_FAILURE);
 122     }
 123
 124   for (i = optind; i < argc; i++)
 125     {
 126       double s;
 127       const char *p;
 128       if (! xstrtod (argv[i], &p, &s, c_strtod)
 129           /* Nonnegative interval.  */
 130           || ! (0 <= s)
 131           /* No extra chars after the number and an optional s,m,h,d char.  */
 132           || (*p && *(p+1))
 133           /* Check any suffix char and update S based on the suffix.  */
 134           || ! apply_suffix (&s, *p))
 135         {
 136           error (0, 0, _("invalid time interval %s"), quote (argv[i]));
 137           ok = false;
 138         }
 139
 140       seconds += s;
 141     }
 142
 143   if (!ok)
 144     usage (EXIT_FAILURE);
 145
 146   if (xnanosleep (seconds))
 147     error (EXIT_FAILURE, errno, _("cannot read realtime clock"));
 148
 149   exit (EXIT_SUCCESS);
 150 }