lib/long-options.c

   1 /* Utility to accept --help and --version options as unobtrusively as possible.
   2    Copyright (C) 1993, 1994, 1998, 1999 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 Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* Written by Jim Meyering.  */
  19
  20 #if HAVE_CONFIG_H
  21 # include <config.h>
  22 #endif
  23
  24 #include <stdio.h>
  25 #include <getopt.h>
  26 #include "closeout.h"
  27 #include "long-options.h"
  28
  29 static struct option const long_options[] =
  30 {
  31   {"help", no_argument, 0, 'h'},
  32   {"version", no_argument, 0, 'v'},
  33   {0, 0, 0, 0}
  34 };
  35
  36 /* Process long options --help and --version, but only if argc == 2.
  37    Be careful not to gobble up `--'.  */
  38
  39 void
  40 parse_long_options (int argc, char **argv, const char *command_name,
  41                     const char *package, const char *version,
  42                     void (*usage_func)())
  43 {
  44   int c;
  45   int saved_opterr;
  46
  47   saved_opterr = opterr;
  48
  49   /* Don't print an error message for unrecognized options.  */
  50   opterr = 0;
  51
  52   if (argc == 2
  53       && (c = getopt_long (argc, argv, "+", long_options, NULL)) != -1)
  54     {
  55       switch (c)
  56         {
  57         case 'h':
  58           (*usage_func) (0);
  59
  60         case 'v':
  61           printf ("%s (%s) %s\n", command_name, package, version);
  62           close_stdout (); /* FIXME: output failure exit status
  63                               should be settable via an arg.  */
  64           exit (0);
  65
  66         default:
  67           /* Don't process any other long-named options.  */
  68           break;
  69         }
  70     }
  71
  72   /* Restore previous value.  */
  73   opterr = saved_opterr;
  74
  75   /* Reset this to zero so that getopt internals get initialized from
  76      the probably-new parameters when/if getopt is called later.  */
  77   optind = 0;
  78 }