gnu/usr.bin/sort/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 /*
  21  * $DragonFly: src/gnu/usr.bin/sort/long-options.c,v 1.2 2007/11/25 01:28:22 swildner Exp $
  22  */
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <getopt.h>
  31 #include "long-options.h"
  32
  33 static struct option const long_options[] =
  34 {
  35   {"help", no_argument, 0, 'h'},
  36   {"version", no_argument, 0, 'v'},
  37   {0, 0, 0, 0}
  38 };
  39
  40 /* Process long options --help and --version, but only if argc == 2.
  41    Be careful not to gobble up `--'.  */
  42
  43 void
  44 parse_long_options (argc, argv, command_name, version_string, usage)
  45      int argc;
  46      char **argv;
  47      const char *command_name;
  48      const char *version_string;
  49      void (*usage)();
  50 {
  51   int c;
  52   int saved_opterr;
  53   int saved_optind;
  54
  55   saved_opterr = opterr;
  56   saved_optind = optind;
  57
  58   /* Don't print an error message for unrecognized options.  */
  59   opterr = 0;
  60
  61   if (argc == 2
  62       && (c = getopt_long (argc, argv, "+", long_options, (int *) 0)) != EOF)
  63     {
  64       switch (c)
  65         {
  66         case 'h':
  67           (*usage) (0);
  68
  69         case 'v':
  70           printf ("%s - %s\n", command_name, version_string);
  71           exit (0);
  72
  73         default:
  74           /* Don't process any other long-named options.  */
  75           break;
  76         }
  77     }
  78
  79   /* Restore previous value.  */
  80   opterr = saved_opterr;
  81
  82   /* Restore optind in case it has advanced past a leading `--'.  */
  83   optind = saved_optind;
  84 }