1/*	$NetBSD: getopt.c,v 1.27 2005/11/29 03:12:00 christos Exp $	*/
2
3/*
4 * Copyright (c) 1987, 1993, 1994
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__RCSID("$NetBSD: getopt.c,v 1.27 2005/11/29 03:12:00 christos Exp $");
34
35#include "namespace.h"
36
37#include <assert.h>
38#include <errno.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42#include <unistd.h>
43
44#ifdef __weak_alias
45__weak_alias(getopt,_getopt)
46#endif
47
48int	opterr = 1,		/* if error message should be printed */
49	optind = 1,		/* index into parent argv vector */
50	optopt,			/* character checked for validity */
51	optreset;		/* reset getopt */
52char	*optarg;		/* argument associated with option */
53
54#define	BADCH	(int)'?'
55#define	BADARG	(int)':'
56#define	EMSG	""
57
58/*
59 * getopt --
60 *	Parse argc/argv argument vector.
61 */
62int
63getopt(int nargc, char * const nargv[], const char *ostr)
64{
65	static const char *place = EMSG;	/* option letter processing */
66	char *oli;				/* option letter list index */
67
68	_DIAGASSERT(nargv != NULL);
69	_DIAGASSERT(ostr != NULL);
70
71	if (optreset || *place == 0) {		/* update scanning pointer */
72		optreset = 0;
73		place = nargv[optind];
74		if (optind >= nargc || *place++ != '-') {
75			/* Argument is absent or is not an option */
76			place = EMSG;
77			return (-1);
78		}
79		optopt = *place++;
80		if (optopt == '-' && *place == 0) {
81			/* "--" => end of options */
82			++optind;
83			place = EMSG;
84			return (-1);
85		}
86		if (optopt == 0) {
87			/* Solitary '-', treat as a '-' option
88			   if the program (eg su) is looking for it. */
89			place = EMSG;
90			if (strchr(ostr, '-') == NULL)
91				return -1;
92			optopt = '-';
93		}
94	} else
95		optopt = *place++;
96
97	/* See if option letter is one the caller wanted... */
98	if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
99		if (*place == 0)
100			++optind;
101		if (opterr && *ostr != ':')
102			(void)fprintf(stderr,
103			    "%s: unknown option -- %c\n", getprogname(),
104			    optopt);
105		return (BADCH);
106	}
107
108	/* Does this option need an argument? */
109	if (oli[1] != ':') {
110		/* don't need argument */
111		optarg = NULL;
112		if (*place == 0)
113			++optind;
114	} else {
115		/* Option-argument is either the rest of this argument or the
116		   entire next argument. */
117		if (*place)
118			optarg = __UNCONST(place);
119		else if (nargc > ++optind)
120			optarg = nargv[optind];
121		else {
122			/* option-argument absent */
123			place = EMSG;
124			if (*ostr == ':')
125				return (BADARG);
126			if (opterr)
127				(void)fprintf(stderr,
128				    "%s: option requires an argument -- %c\n",
129				    getprogname(), optopt);
130			return (BADCH);
131		}
132		place = EMSG;
133		++optind;
134	}
135	return (optopt);			/* return option letter */
136}
137