/*	$Id: getopt.c 15794 2009-03-18 09:10:28Z moritz $	*/
/*	$OpenBSD: getopt_long.c,v 1.23 2007/10/31 12:34:57 chl Exp $	*/
/*	$NetBSD: getopt_long.c,v 1.15 2002/01/31 22:43:40 tv Exp $	*/

/*
 * Copyright (c) 2002 Todd C. Miller <Todd.Miller@courtesan.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
 */
/*-
 * Copyright (c) 2000 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Dieter Baron and Thomas Klausner.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif /* HAVE_CONFIG_H */

#include "ezstream.h"

int	local_getopt(int, char * const *, const char *);

#ifndef HAVE_GETOPT

int	 opterr = 1;		/* if error message should be printed */
int	 optind = 1;		/* index into parent argv vector */
int	 optopt = '?';		/* character checked for validity */
int	 optreset;		/* reset getopt */
char	*optarg;		/* argument associated with option */

#define PRINT_ERROR	((opterr) && (*options != ':'))

#define FLAG_PERMUTE	0x01	/* permute non-options to the end of argv */
#define FLAG_ALLARGS	0x02	/* treat non-options as args to option "-1" */
#define FLAG_LONGONLY	0x04	/* operate as getopt_long_only */

/* return values */
#define BADCH		(int)'?'
#define BADARG		((*options == ':') ? (int)':' : (int)'?')
#define INORDER 	(int)1

#define EMSG		""

static int getopt_internal(int, char * const *, const char *, int);
static int gcd(int, int);
static void permute_args(int, int, int, char * const *);

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

/* XXX: set optreset to 1 rather than these two */
static int nonopt_start = -1; /* first non option argument (for permute) */
static int nonopt_end = -1;   /* first option after non options (for permute) */

/* Error messages */
static const char recargchar[] = "option requires an argument -- %c\n";
static const char illoptchar[] = "unknown option -- %c\n";

/*
 * Compute the greatest common divisor of a and b.
 */
static int
gcd(int a, int b)
{
	int c;

	c = a % b;
	while (c != 0) {
		a = b;
		b = c;
		c = a % b;
	}

	return (b);
}

/*
 * Exchange the block from nonopt_start to nonopt_end with the block
 * from nonopt_end to opt_end (keeping the same order of arguments
 * in each block).
 */
static void
permute_args(int panonopt_start, int panonopt_end, int opt_end,
	char * const *nargv)
{
	int cstart, cyclelen, i, j, ncycle, nnonopts, nopts, pos;
	char *swap;

	/*
	 * compute lengths of blocks and number and size of cycles
	 */
	nnonopts = panonopt_end - panonopt_start;
	nopts = opt_end - panonopt_end;
	ncycle = gcd(nnonopts, nopts);
	cyclelen = (opt_end - panonopt_start) / ncycle;

	for (i = 0; i < ncycle; i++) {
		cstart = panonopt_end+i;
		pos = cstart;
		for (j = 0; j < cyclelen; j++) {
			if (pos >= panonopt_end)
				pos -= nnonopts;
			else
				pos += nopts;
			swap = nargv[pos];
			/* LINTED const cast */
			((char **) nargv)[pos] = nargv[cstart];
			/* LINTED const cast */
			((char **)nargv)[cstart] = swap;
		}
	}
}

/*
 * getopt_internal --
 *	Parse argc/argv argument vector.  Called by user level routines.
 */
static int
getopt_internal(int nargc, char * const *nargv, const char *options, int flags)
{
	char *oli;				/* option letter list index */
	int optchar;
	static int posixly_correct = -1;

	if (options == NULL)
		return (-1);

	/*
	 * Disable GNU extensions if POSIXLY_CORRECT is set or options
	 * string begins with a '+'.
	 */
	if (posixly_correct == -1)
		posixly_correct = (getenv("POSIXLY_CORRECT") != NULL);
	if (posixly_correct || *options == '+')
		flags &= ~FLAG_PERMUTE;
	else if (*options == '-')
		flags |= FLAG_ALLARGS;
	if (*options == '+' || *options == '-')
		options++;

	/*
	 * XXX Some GNU programs (like cvs) set optind to 0 instead of
	 * XXX using optreset.  Work around this braindamage.
	 */
	if (optind == 0)
		optind = optreset = 1;

	optarg = NULL;
	if (optreset)
		nonopt_start = nonopt_end = -1;
start:
	if (optreset || !*place) {		/* update scanning pointer */
		optreset = 0;
		if (optind >= nargc) {          /* end of argument vector */
			place = EMSG;
			if (nonopt_end != -1) {
				/* do permutation, if we have to */
				permute_args(nonopt_start, nonopt_end,
				    optind, nargv);
				optind -= nonopt_end - nonopt_start;
			}
			else if (nonopt_start != -1) {
				/*
				 * If we skipped non-options, set optind
				 * to the first of them.
				 */
				optind = nonopt_start;
			}
			nonopt_start = nonopt_end = -1;
			return (-1);
		}
		if (*(place = nargv[optind]) != '-' ||
		    (place[1] == '\0' && strchr(options, '-') == NULL)) {
			place = EMSG;		/* found non-option */
			if (flags & FLAG_ALLARGS) {
				/*
				 * GNU extension:
				 * return non-option as argument to option 1
				 */
				optarg = nargv[optind++];
				return (INORDER);
			}
			if (!(flags & FLAG_PERMUTE)) {
				/*
				 * If no permutation wanted, stop parsing
				 * at first non-option.
				 */
				return (-1);
			}
			/* do permutation */
			if (nonopt_start == -1)
				nonopt_start = optind;
			else if (nonopt_end != -1) {
				permute_args(nonopt_start, nonopt_end,
				    optind, nargv);
				nonopt_start = optind -
				    (nonopt_end - nonopt_start);
				nonopt_end = -1;
			}
			optind++;
			/* process next argument */
			goto start;
		}
		if (nonopt_start != -1 && nonopt_end == -1)
			nonopt_end = optind;

		/*
		 * If we have "-" do nothing, if "--" we are done.
		 */
		if (place[1] != '\0' && *++place == '-' && place[1] == '\0') {
			optind++;
			place = EMSG;
			/*
			 * We found an option (--), so if we skipped
			 * non-options, we have to permute.
			 */
			if (nonopt_end != -1) {
				permute_args(nonopt_start, nonopt_end,
				    optind, nargv);
				optind -= nonopt_end - nonopt_start;
			}
			nonopt_start = nonopt_end = -1;
			return (-1);
		}
	}

	if ((optchar = (int)*place++) == (int)':' ||
	    (optchar == (int)'-' && *place != '\0') ||
	    (oli = strchr(options, optchar)) == NULL) {
		/*
		 * If the user specified "-" and  '-' isn't listed in
		 * options, return -1 (non-option) as per POSIX.
		 * Otherwise, it is an unknown option character (or ':').
		 */
		if (optchar == (int)'-' && *place == '\0')
			return (-1);
		if (!*place)
			++optind;
		if (PRINT_ERROR)
			fprintf(stderr, illoptchar, optchar);
		optopt = optchar;
		return (BADCH);
	}
	if (*++oli != ':') {			/* doesn't take argument */
		if (!*place)
			++optind;
	} else {				/* takes (optional) argument */
		optarg = NULL;
		if (*place)			/* no white space */
			optarg = place;
		else if (oli[1] != ':') {	/* arg not optional */
			if (++optind >= nargc) {	/* no arg */
				place = EMSG;
				if (PRINT_ERROR)
					fprintf(stderr, recargchar, optchar);
				optopt = optchar;
				return (BADARG);
			} else
				optarg = nargv[optind];
		}
		place = EMSG;
		++optind;
	}
	/* dump back option letter */
	return (optchar);
}

#endif /* !HAVE_GETOPT */

/*
 * getopt --
 *	Parse argc/argv argument vector.
 *
 * [eventually this will replace the BSD getopt]
 */
int
local_getopt(int nargc, char * const *nargv, const char *options)
{
#ifdef HAVE_GETOPT
	return (getopt(nargc, nargv, options));
#else /* HAVE_GETOPT */

	/*
	 * We don't pass FLAG_PERMUTE to getopt_internal() since
	 * the BSD getopt(3) (unlike GNU) has never done this.
	 *
	 * Furthermore, since many privileged programs call getopt()
	 * before dropping privileges it makes sense to keep things
	 * as simple (and bug-free) as possible.
	 */
	return (getopt_internal(nargc, nargv, options, 0));
#endif /* HAVE_GETOPT */
}
