/* Example of Parsing Arguments with getopt.

   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/>.

*/

/*@group*/

#include <ctype.h>

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

int

main (int argc, char **argv)

{

  int aflag = 0;

  int bflag = 0;

  char *cvalue = NULL;

  int index;

  int c;

  opterr = 0;

/*@end group*/

/*@group*/

  while ((c = getopt (argc, argv, "abc:")) != -1)

    switch (c)

      {

      case 'a':

        aflag = 1;

        break;

      case 'b':

        bflag = 1;

        break;

      case 'c':

        cvalue = optarg;

        break;

      case '?':

        if (optopt == 'c')

          fprintf (stderr, "Option -%c requires an argument.\n", optopt);

        else if (isprint (optopt))

          fprintf (stderr, "Unknown option `-%c'.\n", optopt);

        else

          fprintf (stderr,

                   "Unknown option character `\\x%x'.\n",

                   optopt);

        return 1;

      default:

        abort ();

      }

/*@end group*/

/*@group*/

  printf ("aflag = %d, bflag = %d, cvalue = %s\n",

	  aflag, bflag, cvalue);

  for (index = optind; index < argc; index++)

    printf ("Non-option argument %s\n", argv[index]);

  return 0;

}

/*@end group*/