getopt_long.c

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Author : schwarze
Date : 2020-05-27 22:25:09
Hash : 0025f5bb
Message : This patch fixes one bug and one instance of undesirable behaviour. The bug, present since 4.4BSD, was that a trailing dash in an option group, when the dash is not permitted as an option letter, resulted in the whole option group being returned as an argument, even though the previous option in the group was already parsed as an option: OPTS=abc ./getopt-test -a- -c arg ===>> OPT(a)ARG(-a-)ARG(-c)ARG(arg). Instead, treat the dash as an invalid option and continue parsing options: ===>> OPT(a)ERR(?-)OPT(c)ARG(arg). The undesirable behaviour was that allowing the dash as an option letter only allowed isolated dashes ("-") and trailing dashes in groups ("-a-"), but neither middle dashes in groups ("-a-b"), even though that already partially worked in 4.4BSD, nor leading dashes in groups ("--a"), even though that works on all other BSDs and on glibc. Also, while POSIX does not require that the dash can be used as an option letter at all, arguably, it encourages that letters either be fully supported or not supported at all. It is dubious whether supporting an option letter in some positions but not in others can be considered conforming. This patch makes OpenBSD behaviour identical to FreeBSD and NetBSD, improves compatibility with glibc (except that glibc does not support isolated "-"), improves compatibility with DragonFly (except that DragonFly is buggy when the dash option letter can take an optional argument but that argument is not present), improves compatibility with Illumos and Solaris 11 (except those do not support "-" and mishandle "--a"), and restores 4.4BSD behaviour for "-a-b". In no respect i'm aware of is compatibility with any other systems reduced. For the full rationale, see my mail to tech@ on 30 Mar 2020 14:26:41 +0200. Part of the problem was originally reported by an anonymous coward on tech@ on 12 Mar 2020 03:40:24 +0200, additional analysis was contributed by martijn@, and then the OP sent the final version of the patch i'm now committing on 17 Mar 2020 19:17:56 +0200. No licensing problem here because after the commit, the file does not contain a single word written by the OP. Also, the OP told me in private mail that he intends to publish the patch under the ISC license already contained in the file and that he wishes to be known by the pseudonym "0xef967c36". OK martijn@, and no objection when shown on tech@, but commit delayed to stay clear of the release.

lib/libc/stdlib/getopt_long.c

/*	$OpenBSD: getopt_long.c,v 1.32 2020/05/27 22:25:09 schwarze Exp $	*/
/*	$NetBSD: getopt_long.c,v 1.15 2002/01/31 22:43:40 tv Exp $	*/

/*
 * Copyright (c) 2002 Todd C. Miller <millert@openbsd.org>
 *
 * 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.
 */

#include <err.h>
#include <errno.h>
#include <getopt.h>
#include <stdlib.h>
#include <string.h>

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 */

#if 0
/* DEF_* only work on initialized (non-COMMON) variables */
DEF_WEAK(opterr);
DEF_WEAK(optind);
DEF_WEAK(optopt);
#endif

#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 *,
			   const struct option *, int *, int);
static int parse_long_options(char * const *, const char *,
			      const struct option *, int *, int, 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";
static const char recargstring[] = "option requires an argument -- %s";
static const char ambig[] = "ambiguous option -- %.*s";
static const char noarg[] = "option doesn't take an argument -- %.*s";
static const char illoptchar[] = "unknown option -- %c";
static const char illoptstring[] = "unknown option -- %s";

/*
 * 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];
			((char **)nargv)[pos] = nargv[cstart];
			((char **)nargv)[cstart] = swap;
		}
	}
}

/*
 * parse_long_options --
 *	Parse long options in argc/argv argument vector.
 * Returns -1 if short_too is set and the option does not match long_options.
 */
static int
parse_long_options(char * const *nargv, const char *options,
	const struct option *long_options, int *idx, int short_too, int flags)
{
	char *current_argv, *has_equal;
	size_t current_argv_len;
	int i, match, exact_match, second_partial_match;

	current_argv = place;
	match = -1;
	exact_match = 0;
	second_partial_match = 0;

	optind++;

	if ((has_equal = strchr(current_argv, '=')) != NULL) {
		/* argument found (--option=arg) */
		current_argv_len = has_equal - current_argv;
		has_equal++;
	} else
		current_argv_len = strlen(current_argv);

	for (i = 0; long_options[i].name; i++) {
		/* find matching long option */
		if (strncmp(current_argv, long_options[i].name,
		    current_argv_len))
			continue;

		if (strlen(long_options[i].name) == current_argv_len) {
			/* exact match */
			match = i;
			exact_match = 1;
			break;
		}
		/*
		 * If this is a known short option, don't allow
		 * a partial match of a single character.
		 */
		if (short_too && current_argv_len == 1)
			continue;

		if (match == -1)	/* first partial match */
			match = i;
		else if ((flags & FLAG_LONGONLY) ||
		    long_options[i].has_arg != long_options[match].has_arg ||
		    long_options[i].flag != long_options[match].flag ||
		    long_options[i].val != long_options[match].val)
			second_partial_match = 1;
	}
	if (!exact_match && second_partial_match) {
		/* ambiguous abbreviation */
		if (PRINT_ERROR)
			warnx(ambig, (int)current_argv_len, current_argv);
		optopt = 0;
		return (BADCH);
	}
	if (match != -1) {		/* option found */
		if (long_options[match].has_arg == no_argument
		    && has_equal) {
			if (PRINT_ERROR)
				warnx(noarg, (int)current_argv_len,
				     current_argv);
			/*
			 * XXX: GNU sets optopt to val regardless of flag
			 */
			if (long_options[match].flag == NULL)
				optopt = long_options[match].val;
			else
				optopt = 0;
			return (BADARG);
		}
		if (long_options[match].has_arg == required_argument ||
		    long_options[match].has_arg == optional_argument) {
			if (has_equal)
				optarg = has_equal;
			else if (long_options[match].has_arg ==
			    required_argument) {
				/*
				 * optional argument doesn't use next nargv
				 */
				optarg = nargv[optind++];
			}
		}
		if ((long_options[match].has_arg == required_argument)
		    && (optarg == NULL)) {
			/*
			 * Missing argument; leading ':' indicates no error
			 * should be generated.
			 */
			if (PRINT_ERROR)
				warnx(recargstring,
				    current_argv);
			/*
			 * XXX: GNU sets optopt to val regardless of flag
			 */
			if (long_options[match].flag == NULL)
				optopt = long_options[match].val;
			else
				optopt = 0;
			--optind;
			return (BADARG);
		}
	} else {			/* unknown option */
		if (short_too) {
			--optind;
			return (-1);
		}
		if (PRINT_ERROR)
			warnx(illoptstring, current_argv);
		optopt = 0;
		return (BADCH);
	}
	if (idx)
		*idx = match;
	if (long_options[match].flag) {
		*long_options[match].flag = long_options[match].val;
		return (0);
	} else
		return (long_options[match].val);
}

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

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

	/*
	 * 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;

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

	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);
		}
	}

	/*
	 * Check long options if:
	 *  1) we were passed some
	 *  2) the arg is not just "-"
	 *  3) either the arg starts with -- we are getopt_long_only()
	 */
	if (long_options != NULL && place != nargv[optind] &&
	    (*place == '-' || (flags & FLAG_LONGONLY))) {
		short_too = 0;
		if (*place == '-')
			place++;		/* --foo long option */
		else if (*place != ':' && strchr(options, *place) != NULL)
			short_too = 1;		/* could be short option too */

		optchar = parse_long_options(nargv, options, long_options,
		    idx, short_too, flags);
		if (optchar != -1) {
			place = EMSG;
			return (optchar);
		}
	}

	if ((optchar = (int)*place++) == (int)':' ||
	    (oli = strchr(options, optchar)) == NULL) {
		if (!*place)
			++optind;
		if (PRINT_ERROR)
			warnx(illoptchar, optchar);
		optopt = optchar;
		return (BADCH);
	}
	if (long_options != NULL && optchar == 'W' && oli[1] == ';') {
		/* -W long-option */
		if (*place)			/* no space */
			/* NOTHING */;
		else if (++optind >= nargc) {	/* no arg */
			place = EMSG;
			if (PRINT_ERROR)
				warnx(recargchar, optchar);
			optopt = optchar;
			return (BADARG);
		} else				/* white space */
			place = nargv[optind];
		optchar = parse_long_options(nargv, options, long_options,
		    idx, 0, flags);
		place = EMSG;
		return (optchar);
	}
	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)
					warnx(recargchar, optchar);
				optopt = optchar;
				return (BADARG);
			} else
				optarg = nargv[optind];
		}
		place = EMSG;
		++optind;
	}
	/* dump back option letter */
	return (optchar);
}

/*
 * getopt --
 *	Parse argc/argv argument vector.
 */
int
getopt(int nargc, char * const *nargv, const char *options)
{

	/*
	 * 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, NULL, NULL, 0));
}

/*
 * getopt_long --
 *	Parse argc/argv argument vector.
 */
int
getopt_long(int nargc, char * const *nargv, const char *options,
    const struct option *long_options, int *idx)
{

	return (getopt_internal(nargc, nargv, options, long_options, idx,
	    FLAG_PERMUTE));
}

/*
 * getopt_long_only --
 *	Parse argc/argv argument vector.
 */
int
getopt_long_only(int nargc, char * const *nargv, const char *options,
    const struct option *long_options, int *idx)
{

	return (getopt_internal(nargc, nargv, options, long_options, idx,
	    FLAG_PERMUTE|FLAG_LONGONLY));
}

IABSD.fr/src/lib/libc/stdlib/getopt_long.c

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IABSD.fr/src /lib/libc/stdlib/getopt_long.c