1/* $Id: getopt.c 276 2010-06-30 12:18:30Z nijtmans $ */
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#if 0
33static char sccsid[] = "@(#)getopt.c	8.3 (Berkeley) 4/27/95";
34__RCSID("$NetBSD: getopt.c,v 1.26 2003/08/07 16:43:40 agc Exp $");
35#endif
36
37#include <stdio.h>
38#include <string.h>
39
40int	opterr = 1,		/* if error message should be printed */
41	optind = 1,		/* index into parent argv vector */
42	optopt,			/* character checked for validity */
43	optreset;		/* reset getopt */
44char	*optarg;		/* argument associated with option */
45
46#define	BADCH	(int)'?'
47#define	BADARG	(int)':'
48#define	EMSG	""
49
50/*
51 * getopt --
52 *	Parse argc/argv argument vector.
53 */
54int
55getopt(int argc, char * const argv[], const char *optstring)
56{
57	static char *place = EMSG;		/* option letter processing */
58	char *oli;				/* option letter list index */
59
60	if (optreset || *place == 0) {		/* update scanning pointer */
61		optreset = 0;
62		place = argv[optind];
63		if (optind >= argc || *place++ != '-') {
64			/* Argument is absent or is not an option */
65			place = EMSG;
66			return (-1);
67		}
68		optopt = *place++;
69		if (optopt == '-' && *place == 0) {
70			/* "--" => end of options */
71			++optind;
72			place = EMSG;
73			return (-1);
74		}
75		if (optopt == 0) {
76			/* Solitary '-', treat as a '-' option
77			   if the program (eg su) is looking for it. */
78			place = EMSG;
79			if (strchr(optstring, '-') == NULL)
80				return -1;
81			optopt = '-';
82		}
83	} else
84		optopt = *place++;
85
86	/* See if option letter is one the caller wanted... */
87	if (optopt == ':' || (oli = strchr(optstring, optopt)) == NULL) {
88		if (*place == 0)
89			++optind;
90		if (opterr && *optstring != ':')
91			(void)fprintf(stderr,
92                                      "unknown option -- %c\n", optopt);
93		return (BADCH);
94	}
95
96	/* Does this option need an argument? */
97	if (oli[1] != ':') {
98		/* don't need argument */
99		optarg = NULL;
100		if (*place == 0)
101			++optind;
102	} else {
103		/* Option-argument is either the rest of this argument or the
104		   entire next argument. */
105		if (*place)
106			optarg = place;
107		else if (argc > ++optind)
108			optarg = argv[optind];
109		else {
110			/* option-argument absent */
111			place = EMSG;
112			if (*optstring == ':')
113				return (BADARG);
114			if (opterr)
115				(void)fprintf(stderr,
116                                        "option requires an argument -- %c\n",
117                                        optopt);
118			return (BADCH);
119		}
120		place = EMSG;
121		++optind;
122	}
123	return (optopt);			/* return option letter */
124}
125/*
126 * Local Variables:
127 * mode: c
128 * c-basic-offset: 8
129 * fill-column: 78
130 * End:
131 */
132