/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 * Common Development and Distribution License (the "License").

 * You may not use this file except in compliance with the License.

 *

 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

 * or http://www.opensolaris.org/os/licensing.

 * See the License for the specific language governing permissions

 * and limitations under the License.

 *

 * When distributing Covered Code, include this CDDL HEADER in each

 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.

 * If applicable, add the following below this CDDL HEADER, with the

 * fields enclosed by brackets "[]" replaced with your own identifying

 * information: Portions Copyright [yyyy] [name of copyright owner]

 *

 * CDDL HEADER END

 */

/*

 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

/*	Copyright (c) 1988 AT&T	*/

/*	  All Rights Reserved  	*/

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*

 * See getopt(3C) and SUS/XPG getopt() for function definition and

 * requirements.

 *

 * This actual implementation is a bit looser than the specification

 * as it allows any character other than ':' and '(' to be used as

 * a short option character - The specification only guarantees the

 * alnum characters ([a-z][A-Z][0-9]).

 */

#pragma weak _getopt = getopt

#include "lint.h"

#include "_libc_gettext.h"

#include <unistd.h>

#include <string.h>

#include <stdio.h>

/*

 * Generalized error processing macro. The parameter i is a pointer to

 * the failed option string. If it is NULL, the character in c is converted

 * to a string and displayed instead. s is the error text.

 *

 * This could be / should be a static function if it is used more, but

 * that would require moving the 'optstring[0]' test outside of the

 * function.

 */

#define	ERR(s, c, i)	if (opterr && optstring[0] != ':') { \

	char errbuf[256]; \

	char cbuf[2]; \

	cbuf[0] = c; \

	cbuf[1] = '\0'; \

	(void) snprintf(errbuf, sizeof (errbuf), s, argv[0], \

	    (i ? argv[i]+2 : cbuf)); \

	(void) write(2, errbuf, strlen(errbuf)); }

/*

 * _sp is required to keep state between successive calls to getopt() while

 * extracting aggregated short-options (ie: -abcd). Hence, getopt() is not

 * thread safe or reentrant, but it really doesn't matter.

 *

 * So, why isn't this "static" you ask?  Because the historical Bourne

 * shell has actually latched on to this little piece of private data.

 */

int _sp = 1;

/*

 * Determine if the specified character (c) is present in the string

 * (optstring) as a regular, single character option. If the option is found,

 * return a pointer into optstring pointing at the short-option character,

 * otherwise return null. The characters ':' and '(' are not allowed.

 */

static char *

parseshort(const char *optstring, const char c)

{

	char *cp = (char *)optstring;

	if (c == ':' || c == '(')

		return (NULL);

	do {

		if (*cp == c)

			return (cp);

		while (*cp == '(')

			while (*cp != '\0' && *cp != ')')

				cp++;

	} while (*cp++ != '\0');

	return (NULL);

}

/*

 * Determine if the specified string (opt) is present in the string

 * (optstring) as a long-option contained within parenthesis. If the

 * long-option specifies option-argument, return a pointer to it in

 * longoptarg.  Otherwise set longoptarg to null. If the option is found,

 * return a pointer into optstring pointing at the short-option character

 * associated with this long-option; otherwise return null.

 *

 * optstring 	The entire optstring passed to getopt() by the caller

 *

 * opt		The long option read from the command line

 *

 * longoptarg	The argument to the option is returned in this parameter,

 *              if an option exists. Possible return values in longoptarg

 *              are:

 *                  NULL		No argument was found

 *		    empty string ("")	Argument was explicitly left empty

 *					by the user (e.g., --option= )

 *		    valid string	Argument found on the command line

 *

 * returns	Pointer to equivalent short-option in optstring, null

 *              if option not found in optstring.

 *

 * ASSUMES: No parameters are NULL

 *

 */

static char *

parselong(const char *optstring, const char *opt, char **longoptarg)

{

	char	*cp;	/* ptr into optstring, beginning of one option spec. */

	char	*ip;	/* ptr into optstring, traverses every char */

	char	*op;	/* pointer into opt */

	int	match;	/* nonzero if opt is matching part of optstring */

	cp = ip = (char *)optstring;

	do {

		if (*ip != '(' && *++ip == '\0')

			break;

		if (*ip == ':' && *++ip == '\0')

			break;

		while (*ip == '(') {

			if (*++ip == '\0')

				break;

			op = (char *)opt;

			match = 1;

			while (*ip != ')' && *ip != '\0' && *op != '\0')

				match = (*ip++ == *op++ && match);

			if (match && *ip == ')' &&

			    (*op == '\0' || *op == '=')) {

				if ((*op) == '=') {

					/* may be an empty string - OK */

					(*longoptarg) = op + 1;

				} else {

					(*longoptarg) = NULL;

				}

				return (cp);

			}

			if (*ip == ')' && *++ip == '\0')

				break;

		}

		cp = ip;

		/*

		 * Handle double-colon in optstring ("a::(longa)")

		 * The old getopt() accepts it and treats it as a

		 * required argument.

		 */

		while ((cp > optstring) && ((*cp) == ':')) {

			--cp;

		}

	} while (*cp != '\0');

	return (NULL);

} /* parselong() */

/*

 * External function entry point.

 */

int

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

{

	char	c;

	char	*cp;

	int	longopt;

	char	*longoptarg;

	/*

	 * Has the end of the options been encountered?  The following

	 * implements the SUS requirements:

	 *

	 * If, when getopt() is called:

	 *	argv[optind]	is a null pointer

	 *	*argv[optind]	is not the character '-'

	 *	argv[optind]	points to the string "-"

	 * getopt() returns -1 without changing optind. If

	 *	argv[optind]	points to the string "--"

	 * getopt() returns -1 after incrementing optind.

	 */

	if (_sp == 1) {

		if (optind >= argc || argv[optind][0] != '-' ||

		    argv[optind] == NULL || argv[optind][1] == '\0')

			return (EOF);

		else if (strcmp(argv[optind], "--") == NULL) {

			optind++;

			return (EOF);

		}

	}

	/*

	 * Getting this far indicates that an option has been encountered.

	 * Note that the syntax of optstring applies special meanings to

	 * the characters ':' and '(', so they are not permissible as

	 * option letters. A special meaning is also applied to the ')'

	 * character, but its meaning can be determined from context.

	 * Note that the specification only requires that the alnum

	 * characters be accepted.

	 *

	 * If the second character of the argument is a '-' this must be

	 * a long-option, otherwise it must be a short option.  Scan for

	 * the option in optstring by the appropriate algorithm. Either

	 * scan will return a pointer to the short-option character in

	 * optstring if the option is found and NULL otherwise.

	 *

	 * For an unrecognized long-option, optopt will equal 0, but

	 * since long-options can't aggregate the failing option can

	 * be identified by argv[optind-1].

	 */

	optopt = c = (unsigned char)argv[optind][_sp];

	optarg = NULL;

	longopt = (_sp == 1 && c == '-');

	if (!(longopt ?

	    ((cp = parselong(optstring, argv[optind]+2, &longoptarg)) != NULL) :

	    ((cp = parseshort(optstring, c)) != NULL))) {

		ERR(_libc_gettext("%s: illegal option -- %s\n"),

		    c, (longopt ? optind : 0));

		/*

		 * Note: When the long option is unrecognized, optopt

		 * will be '-' here, which matches the specification.

		 */

		if (argv[optind][++_sp] == '\0' || longopt) {

			optind++;

			_sp = 1;

		}

		return ('?');

	}

	optopt = c = *cp;

	/*

	 * A valid option has been identified.  If it should have an

	 * option-argument, process that now.  SUS defines the setting

	 * of optarg as follows:

	 *

	 *   1.	If the option was the last character in the string pointed to

	 *	by an element of argv, then optarg contains the next element

	 *	of argv, and optind is incremented by 2. If the resulting

	 *	value of optind is not less than argc, this indicates a

	 *	missing option-argument, and getopt() returns an error

	 *	indication.

	 *

	 *   2.	Otherwise, optarg points to the string following the option

	 *	character in that element of argv, and optind is incremented

	 *	by 1.

	 *

	 * The second clause allows -abcd (where b requires an option-argument)

	 * to be interpreted as "-a -b cd".

	 *

	 * Note that the option-argument can legally be an empty string,

	 * such as:

	 * 	command --option= operand

	 * which explicitly sets the value of --option to nil

	 */

	if (*(cp + 1) == ':') {

		/* The option takes an argument */

		if (!longopt && argv[optind][_sp+1] != '\0') {

			optarg = &argv[optind++][_sp+1];

		} else if (longopt && longoptarg) {

			/*

			 * The option argument was explicitly set to

			 * the empty string on the command line (--option=)

			 */

			optind++;

			optarg = longoptarg;

		} else if (++optind >= argc) {

			ERR(_libc_gettext("%s: option requires an argument" \

			    " -- %s\n"), c, (longopt ? optind - 1 : 0));

			_sp = 1;

			optarg = NULL;

			return (optstring[0] == ':' ? ':' : '?');

		} else

			optarg = argv[optind++];

		_sp = 1;

	} else {

		/* The option does NOT take an argument */

		if (longopt && (longoptarg != NULL)) {

			/* User supplied an arg to an option that takes none */

			ERR(_libc_gettext(

			    "%s: option doesn't take an argument -- %s\n"),

			    0, (longopt ? optind : 0));

			optarg = longoptarg = NULL;

			c = '?';

		}

		if (longopt || argv[optind][++_sp] == '\0') {

			_sp = 1;

			optind++;

		}

		optarg = NULL;

	}

	return (c);

} /* getopt() */