/* $Id: getopt.c,v 1.2 2005/07/07 16:34:06 dron Exp $ */

/*

 * Copyright (c) 1987, 1993, 1994

 *	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:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. 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.

 * 3. Neither the name of the University 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 REGENTS 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 0

static char sccsid[] = "@(#)getopt.c	8.3 (Berkeley) 4/27/95";

__RCSID("$NetBSD: getopt.c,v 1.26 2003/08/07 16:43:40 agc Exp $");

#endif

#include <stdio.h>

#include <string.h>

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

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

	optopt,			/* character checked for validity */

	optreset;		/* reset getopt */

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

#define	BADCH	(int)'?'

#define	BADARG	(int)':'

#define	EMSG	""

/*

 * getopt --

 *	Parse argc/argv argument vector.

 */

int

getopt(int argc, char * const argv[], const char *optstring)

{

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

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

	if (optreset || *place == 0) {		/* update scanning pointer */

		optreset = 0;

		place = argv[optind];

		if (optind >= argc || *place++ != '-') {

			/* Argument is absent or is not an option */

			place = EMSG;

			return (-1);

		}

		optopt = *place++;

		if (optopt == '-' && *place == 0) {

			/* "--" => end of options */

			++optind;

			place = EMSG;

			return (-1);

		}

		if (optopt == 0) {

			/* Solitary '-', treat as a '-' option

			   if the program (eg su) is looking for it. */

			place = EMSG;

			if (strchr(optstring, '-') == NULL)

				return -1;

			optopt = '-';

		}

	} else

		optopt = *place++;

	/* See if option letter is one the caller wanted... */

	if (optopt == ':' || (oli = strchr(optstring, optopt)) == NULL) {

		if (*place == 0)

			++optind;

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

			(void)fprintf(stderr,

                                      "unknown option -- %c\n", optopt);

		return (BADCH);

	}

	/* Does this option need an argument? */

	if (oli[1] != ':') {

		/* don't need argument */

		optarg = NULL;

		if (*place == 0)

			++optind;

	} else {

		/* Option-argument is either the rest of this argument or the

		   entire next argument. */

		if (*place)

			optarg = place;

		else if (argc > ++optind)

			optarg = argv[optind];

		else {

			/* option-argument absent */

			place = EMSG;

			if (*optstring == ':')

				return (BADARG);

			if (opterr)

				(void)fprintf(stderr,

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

                                        optopt);

			return (BADCH);

		}

		place = EMSG;

		++optind;

	}

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

}