lib/long-options.c

   1 /* Utility to accept --help and --version options as unobtrusively as possible.
   2    Copyright (C) 1993, 1994 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 2, or (at your option)
   7    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, write to the Free Software
  16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  17
  18 /* Jim Meyering (meyering@comco.com) */
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include <config.h>
  22 #endif
  23
  24 #include <stdio.h>
  25 #include <getopt.h>
  26 #include "long-options.h"
  27
  28 static struct option const long_options[] =
  29 {
  30   {"help", no_argument, 0, 'h'},
  31   {"version", no_argument, 0, 'v'},
  32   {0, 0, 0, 0}
  33 };
  34
  35 /* Process long options --help and --version, but only if argc == 2.
  36    Be careful not to gobble up `--'.  */
  37
  38 void
  39 parse_long_options (argc, argv, command_name, version_string, usage)
  40      int argc;
  41      char **argv;
  42      const char *command_name;
  43      const char *version_string;
  44      void (*usage)();
  45 {
  46   int c;
  47   int saved_opterr;
  48   int saved_optind;
  49
  50   saved_opterr = opterr;
  51   saved_optind = optind;
  52
  53   /* Don't print an error message for unrecognized options.  */
  54   opterr = 0;
  55
  56   if (argc == 2
  57       && (c = getopt_long (argc, argv, "+", long_options, (int *) 0)) != EOF)
  58     {
  59       switch (c)
  60         {
  61         case 'h':
  62           (*usage) (0);
  63
  64         case 'v':
  65           printf ("%s - %s\n", command_name, version_string);
  66           exit (0);
  67
  68         default:
  69           /* Don't process any other long-named options.  */
  70           break;
  71         }
  72     }
  73
  74   /* Restore previous value.  */
  75   opterr = saved_opterr;
  76
  77   /* Restore optind in case it has advanced past a leading `--'.  */
  78   optind = saved_optind;
  79 }