/*

 * Original file name getopt.c  Initial import into the c-ares source tree

 * on 2007-04-11.  Lifted from version 5.2 of the 'Open Mash' project with

 * the modified BSD license, BSD license without the advertising clause.

 *

 */

/*

 * getopt.c --

 *

 *      Standard UNIX getopt function.  Code is from BSD.

 *

 * Copyright (c) 1987-2001 The Regents of the University of California.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 * A. Redistributions of source code must retain the above copyright notice,

 *    this list of conditions and the following disclaimer.

 * B. Redistributions in binary form must reproduce the above copyright notice,

 *    this list of conditions and the following disclaimer in the documentation

 *    and/or other materials provided with the distribution.

 * C. Neither the names of the copyright holders nor the names of its

 *    contributors may be used to endorse or promote products derived from this

 *    software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS

 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE

 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGE.

 */

/* #if !defined(lint)

 * static char sccsid[] = "@(#)getopt.c 8.2 (Berkeley) 4/2/94";

 * #endif

 */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "ares_getopt.h"

int   opterr = 1,     /* if error message should be printed */

      optind = 1;     /* index into parent argv vector */

int   optopt = 0;     /* character checked for validity */

static int optreset;  /* reset getopt */

char  *optarg;        /* argument associated with option */

#define  BADCH   (int)'?'

#define  BADARG  (int)':'

#define  EMSG    (char *)""

/*

 * ares_getopt --

 *    Parse argc/argv argument vector.

 */

int

ares_getopt(int nargc, char * const nargv[], const char *ostr)

{

    static char *place = EMSG;                /* option letter processing */

    char *oli;                                /* option letter list index */

    if (optreset || !*place) {                /* update scanning pointer */

        optreset = 0;

        if (optind >= nargc || *(place = nargv[optind]) != '-') {

            place = EMSG;

            return (EOF);

        }

        if (place[1] && *++place == '-') {    /* found "--" */

            ++optind;

            place = EMSG;

            return (EOF);

        }

    }                                         /* option letter okay? */

    if ((optopt = (int)*place++) == (int)':' ||

        (oli = strchr(ostr, optopt)) == NULL) {

        /*

         * if the user didn't specify '-' as an option,

         * assume it means EOF.

         */

        if (optopt == (int)'-')

            return (EOF);

        if (!*place)

            ++optind;

        if (opterr && *ostr != ':')

            (void)fprintf(stderr,

                "%s: illegal option -- %c\n", __FILE__, optopt);

        return (BADCH);

    }

    if (*++oli != ':') {                      /* don't need argument */

        optarg = NULL;

        if (!*place)

            ++optind;

    }

    else {                                    /* need an argument */

        if (*place)                           /* no white space */

            optarg = place;

        else if (nargc <= ++optind) {         /* no arg */

            place = EMSG;

            if (*ostr == ':')

                return (BADARG);

            if (opterr)

                (void)fprintf(stderr,

                    "%s: option requires an argument -- %c\n",

                    __FILE__, optopt);

            return (BADCH);

        }

         else                                 /* white space */

            optarg = nargv[optind];

        place = EMSG;

        ++optind;

    }

    return (optopt);                          /* dump back option letter */

}