getopt.c

/*
 * This file is part of the Advance project.
 *
 * Copyright (C) 2002 Andrea Mazzoleni
 *
 * 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.
 */

#if HAVE_CONFIG_H
#include <config.h>
#endif

#if !HAVE_GETOPT

/* This source is extracted from the DJGPP LIBC library */

#define unconst(var, type) ((type)(var))

/* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
#include <string.h>
#include <stdio.h>

int opterr = 1, optind = 1, optopt = 0;
char *optarg = 0;

#define BADCH (int)'?'
#define EMSG ""

int getopt(int nargc, char *const nargv[], const char *ostr)
{
	static const char *place = EMSG; /* option letter processing */
	char *oli; /* option letter list index */
	char *p;

	if (!*place) {
		if (optind >= nargc || *(place = nargv[optind]) != '-') {
			place = EMSG;
			return EOF;
		}
		if (place[1] && *++place == '-') {
			++optind;
			place = EMSG;
			return EOF;
		}
	}

	if ((optopt = (int)*place++) == (int)':'
		|| !(oli = strchr(ostr, optopt))) {
		/*
		 * if the user didn't specify '-' as an option,
		 * assume it means EOF.
		 */
		if (optopt == (int)'-')
			return EOF;
		if (!*place)
			++optind;
		if (opterr) {
			if (!(p = strrchr(*nargv, '/')))
				p = *nargv;
			else
				++p;
			fprintf(stderr, "%s: illegal option -- %c\n", p, optopt);
		}
		return BADCH;
	}
	if (*++oli != ':') { /* don't need argument */
		optarg = NULL;
		if (!*place)
			++optind;
	} else { /* need an argument */
		if (*place) /* no white space */
			optarg = unconst(place, char *);
		else if (nargc <= ++optind) { /* no arg */
			place = EMSG;
			if (!(p = strrchr(*nargv, '/')))
				p = *nargv;
			else
				++p;
			if (opterr)
				fprintf(stderr, "%s: option requires an argument -- %c\n", p, optopt);
			return BADCH;
		}else /* white space */
			optarg = nargv[optind];
		place = EMSG;
		++optind;
	}
	return optopt; /* dump back option letter */
}

#endif