manual/examples/longopt.c

   1 /* Example of Parsing Long Options with getopt_long.
   2    Copyright (C) 1991-2016 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU General Public License
   6    as published by the Free Software Foundation; either version 2
   7    of the License, or (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, if not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <getopt.h>
  21
  22 /* Flag set by @samp{--verbose}.  */
  23 static int verbose_flag;
  24
  25 int
  26 main (int argc, char **argv)
  27 {
  28   int c;
  29
  30   while (1)
  31     {
  32       static struct option long_options[] =
  33         {
  34           /* These options set a flag.  */
  35           {"verbose", no_argument,       &verbose_flag, 1},
  36           {"brief",   no_argument,       &verbose_flag, 0},
  37           /* These options don't set a flag.
  38              We distinguish them by their indices.  */
  39           {"add",     no_argument,       0, 'a'},
  40           {"append",  no_argument,       0, 'b'},
  41           {"delete",  required_argument, 0, 'd'},
  42           {"create",  required_argument, 0, 'c'},
  43           {"file",    required_argument, 0, 'f'},
  44           {0, 0, 0, 0}
  45         };
  46       /* @code{getopt_long} stores the option index here.  */
  47       int option_index = 0;
  48
  49       c = getopt_long (argc, argv, "abc:d:f:",
  50                        long_options, &option_index);
  51
  52       /* Detect the end of the options.  */
  53       if (c == -1)
  54         break;
  55
  56       switch (c)
  57         {
  58         case 0:
  59           /* If this option set a flag, do nothing else now.  */
  60           if (long_options[option_index].flag != 0)
  61             break;
  62           printf ("option %s", long_options[option_index].name);
  63           if (optarg)
  64             printf (" with arg %s", optarg);
  65           printf ("\n");
  66           break;
  67
  68         case 'a':
  69           puts ("option -a\n");
  70           break;
  71
  72         case 'b':
  73           puts ("option -b\n");
  74           break;
  75
  76         case 'c':
  77           printf ("option -c with value `%s'\n", optarg);
  78           break;
  79
  80         case 'd':
  81           printf ("option -d with value `%s'\n", optarg);
  82           break;
  83
  84         case 'f':
  85           printf ("option -f with value `%s'\n", optarg);
  86           break;
  87
  88         case '?':
  89           /* @code{getopt_long} already printed an error message.  */
  90           break;
  91
  92         default:
  93           abort ();
  94         }
  95     }
  96
  97   /* Instead of reporting @samp{--verbose}
  98      and @samp{--brief} as they are encountered,
  99      we report the final status resulting from them.  */
 100   if (verbose_flag)
 101     puts ("verbose flag is set");
 102
 103   /* Print any remaining command line arguments (not options).  */
 104   if (optind < argc)
 105     {
 106       printf ("non-option ARGV-elements: ");
 107       while (optind < argc)
 108         printf ("%s ", argv[optind++]);
 109       putchar ('\n');
 110     }
 111
 112   exit (0);
 113 }