src/true.c

   1 /* Exit with a status code indicating success.
   2    Copyright (C) 1999-2019 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 #include "system.h"
  21
  22 /* Act like "true" by default; false.c overrides this.  */
  23 #ifndef EXIT_STATUS
  24 # define EXIT_STATUS EXIT_SUCCESS
  25 #endif
  26
  27 #if EXIT_STATUS == EXIT_SUCCESS
  28 # define PROGRAM_NAME "true"
  29 #else
  30 # define PROGRAM_NAME "false"
  31 #endif
  32
  33 #define AUTHORS proper_name ("Jim Meyering")
  34
  35 void
  36 usage (int status)
  37 {
  38   printf (_("\
  39 Usage: %s [ignored command line arguments]\n\
  40   or:  %s OPTION\n\
  41 "),
  42           program_name, program_name);
  43   printf ("%s\n\n",
  44           _(EXIT_STATUS == EXIT_SUCCESS
  45             ? N_("Exit with a status code indicating success.")
  46             : N_("Exit with a status code indicating failure.")));
  47   fputs (HELP_OPTION_DESCRIPTION, stdout);
  48   fputs (VERSION_OPTION_DESCRIPTION, stdout);
  49   printf (USAGE_BUILTIN_WARNING, PROGRAM_NAME);
  50   emit_ancillary_info (PROGRAM_NAME);
  51   exit (status);
  52 }
  53
  54 int
  55 main (int argc, char **argv)
  56 {
  57   /* Recognize --help or --version only if it's the only command-line
  58      argument.  */
  59   if (argc == 2)
  60     {
  61       initialize_main (&argc, &argv);
  62       set_program_name (argv[0]);
  63       setlocale (LC_ALL, "");
  64       bindtextdomain (PACKAGE, LOCALEDIR);
  65       textdomain (PACKAGE);
  66
  67       /* Note true(1) will return EXIT_FAILURE in the
  68          edge case where writes fail with GNU specific options.  */
  69       atexit (close_stdout);
  70
  71       if (STREQ (argv[1], "--help"))
  72         usage (EXIT_STATUS);
  73
  74       if (STREQ (argv[1], "--version"))
  75         version_etc (stdout, PROGRAM_NAME, PACKAGE_NAME, Version, AUTHORS,
  76                      (char *) NULL);
  77     }
  78
  79   return EXIT_STATUS;
  80 }