/*

   getopt_long.c - implementation of getopt_long() for systems that lack it

   Copyright (C) 2001, 2002, 2008, 2012 Arthur de Jong

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

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   This library 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

   Lesser General Public License for more details.

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

   License along with this library; if not, write to the Free Software

   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

   02110-1301 USA

*/

#include <stdlib.h>

#include <unistd.h>

#include <string.h>

#include "getopt_long.h"

/* this is a (poor) getopt_long() replacement for systems that don't have it

   (getopt_long() is generaly a GNU extention)

   this implementation is by no meens flawless, especialy the optional arguments

   to options and options following filenames is not quite right, allso

   minimal error checking is provided

   */

int getopt_long(int argc, char *const argv[],

                const char *optstring,

                const struct option *longopts, int *longindex)

{

  int i, l;

  /* first check if there realy is a -- option */

  if ((optind > 0) && (optind < argc) &&

      (strncmp(argv[optind], "--", 2) == 0) &&

      (argv[optind][2] != '\0'))

  {

    /* check the longopts list for a valid option */

    for (i = 0; longopts[i].name != NULL; i++)

    {

      /* save the length for later */

      l = strlen(longopts[i].name);

      if (strncmp(argv[optind] + 2, longopts[i].name, l) == 0)

      {

        /* we have a match */

        if ((longopts[i].has_arg == no_argument) &&

            (argv[optind][2 + l] == '\0'))

        {

          optind++;

          return longopts[i].val;

        }

        else if ((longopts[i].has_arg == required_argument) &&

                 (argv[optind][2 + l] == '='))

        {

          optarg = argv[optind] + 3 + l;

          optind++;

          return longopts[i].val;

        }

        else if ((longopts[i].has_arg == required_argument) &&

                 (argv[optind][2 + l] == '\0'))

        {

          optarg = argv[optind + 1];

          optind += 2;

          return longopts[i].val;

        }

        else if ((longopts[i].has_arg == optional_argument) &&

                 (argv[optind][2 + l] == '='))

        {

          optarg = argv[optind] + 3 + l;

          optind++;

          return longopts[i].val;

        }

        else if ((longopts[i].has_arg == optional_argument) &&

                 (argv[optind][2 + l] == '\0'))

        {

          optind++;

          return longopts[i].val;

        }

      }

    }

  }

  /* if all else fails use plain getopt() */

  return getopt(argc, argv, optstring);

}