lib/long-options.c

   1 /* Utility to accept --help and --version options as unobtrusively as possible.
   2
   3    Copyright (C) 1993, 1994, 1998, 1999, 2000, 2002, 2003, 2004 Free
   4    Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software Foundation,
  18    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 /* Written by Jim Meyering.  */
  21
  22 #if HAVE_CONFIG_H
  23 # include <config.h>
  24 #endif
  25
  26 /* Specification.  */
  27 #include "long-options.h"
  28
  29 #include <stdarg.h>
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <getopt.h>
  33
  34 #include "version-etc.h"
  35
  36 static struct option const long_options[] =
  37 {
  38   {"help", no_argument, 0, 'h'},
  39   {"version", no_argument, 0, 'v'},
  40   {0, 0, 0, 0}
  41 };
  42
  43 /* Process long options --help and --version, but only if argc == 2.
  44    Be careful not to gobble up `--'.  */
  45
  46 void
  47 parse_long_options (int argc,
  48                     char **argv,
  49                     const char *command_name,
  50                     const char *package,
  51                     const char *version,
  52                     void (*usage_func) (int),
  53                     /* const char *author1, ...*/ ...)
  54 {
  55   int c;
  56   int saved_opterr;
  57
  58   saved_opterr = opterr;
  59
  60   /* Don't print an error message for unrecognized options.  */
  61   opterr = 0;
  62
  63   if (argc == 2
  64       && (c = getopt_long (argc, argv, "+", long_options, NULL)) != -1)
  65     {
  66       switch (c)
  67         {
  68         case 'h':
  69           (*usage_func) (EXIT_SUCCESS);
  70
  71         case 'v':
  72           {
  73             va_list authors;
  74             va_start (authors, usage_func);
  75             version_etc_va (stdout, command_name, package, version, authors);
  76             exit (0);
  77           }
  78
  79         default:
  80           /* Don't process any other long-named options.  */
  81           break;
  82         }
  83     }
  84
  85   /* Restore previous value.  */
  86   opterr = saved_opterr;
  87
  88   /* Reset this to zero so that getopt internals get initialized from
  89      the probably-new parameters when/if getopt is called later.  */
  90   optind = 0;
  91 }