/* Example of Parsing Long Options with getopt_long.

   Copyright (C) 1991-2018 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or

   modify it under the terms of the GNU General Public License

   as published by the Free Software Foundation; either version 2

   of the License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program; if not, if not, see <http://www.gnu.org/licenses/>.

*/

#include <stdio.h>

#include <stdlib.h>

#include <getopt.h>

/* Flag set by @samp{--verbose}.  */

static int verbose_flag;

int

main (int argc, char **argv)

{

  int c;

  while (1)

    {

      static struct option long_options[] =

	{

	  /* These options set a flag.  */

	  {"verbose", no_argument,       &verbose_flag, 1},

	  {"brief",   no_argument,       &verbose_flag, 0},

	  /* These options don't set a flag.

	     We distinguish them by their indices.  */

	  {"add",     no_argument,       0, 'a'},

	  {"append",  no_argument,       0, 'b'},

	  {"delete",  required_argument, 0, 'd'},

	  {"create",  required_argument, 0, 'c'},

	  {"file",    required_argument, 0, 'f'},

	  {0, 0, 0, 0}

	};

      /* @code{getopt_long} stores the option index here.  */

      int option_index = 0;

      c = getopt_long (argc, argv, "abc:d:f:",

		       long_options, &option_index);

      /* Detect the end of the options.  */

      if (c == -1)

	break;

      switch (c)

	{

	case 0:

	  /* If this option set a flag, do nothing else now.  */

	  if (long_options[option_index].flag != 0)

	    break;

	  printf ("option %s", long_options[option_index].name);

	  if (optarg)

	    printf (" with arg %s", optarg);

	  printf ("\n");

	  break;

	case 'a':

	  puts ("option -a\n");

	  break;

	case 'b':

	  puts ("option -b\n");

	  break;

	case 'c':

	  printf ("option -c with value `%s'\n", optarg);

	  break;

	case 'd':

	  printf ("option -d with value `%s'\n", optarg);

	  break;

	case 'f':

	  printf ("option -f with value `%s'\n", optarg);

	  break;

	case '?':

	  /* @code{getopt_long} already printed an error message.  */

	  break;

	default:

	  abort ();

	}

    }

  /* Instead of reporting @samp{--verbose}

     and @samp{--brief} as they are encountered,

     we report the final status resulting from them.  */

  if (verbose_flag)

    puts ("verbose flag is set");

  /* Print any remaining command line arguments (not options).  */

  if (optind < argc)

    {

      printf ("non-option ARGV-elements: ");

      while (optind < argc)

	printf ("%s ", argv[optind++]);

      putchar ('\n');

    }

  exit (0);

}