getopt.c revision 267745 
1/*	$NetBSD: getopt.c,v 1.29 2014/06/05 22:00:22 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#if defined(LIBC_SCCS) && !defined(lint)
33static char sccsid[] = "@(#)getopt.c	8.3 (Berkeley) 4/27/95";
34#endif /* LIBC_SCCS and not lint */
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD: head/lib/libc/stdlib/getopt.c 267745 2014-06-22 20:13:57Z pfg $");
37
38#include "namespace.h"
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42#include <unistd.h>
43#include "un-namespace.h"
44
45#include "libc_private.h"
46
47int	opterr = 1,		/* if error message should be printed */
48	optind = 1,		/* index into parent argv vector */
49	optopt,			/* character checked for validity */
50	optreset;		/* reset getopt */
51char	*optarg;		/* argument associated with option */
52
53#define	BADCH	(int)'?'
54#define	BADARG	(int)':'
55#define	EMSG	""
56
57/*
58 * getopt --
59 *	Parse argc/argv argument vector.
60 */
61int
62getopt(int nargc, char * const nargv[], const char *ostr)
63{
64	static char *place = EMSG;		/* option letter processing */
65	char *oli;				/* option letter list index */
66
67	if (optreset || *place == 0) {		/* update scanning pointer */
68		optreset = 0;
69		place = nargv[optind];
70		if (optind >= nargc || *place++ != '-') {
71			/* Argument is absent or is not an option */
72			place = EMSG;
73			return (-1);
74		}
75		optopt = *place++;
76		if (optopt == '-' && *place == 0) {
77			/* "--" => end of options */
78			++optind;
79			place = EMSG;
80			return (-1);
81		}
82		if (optopt == 0) {
83			/* Solitary '-', treat as a '-' option
84			   if the program (eg su) is looking for it. */
85			place = EMSG;
86			if (strchr(ostr, '-') == NULL)
87				return (-1);
88			optopt = '-';
89		}
90	} else
91		optopt = *place++;
92
93	/* See if option letter is one the caller wanted... */
94	if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
95		if (*place == 0)
96			++optind;
97		if (opterr && *ostr != ':')
98			(void)fprintf(stderr,
99			    "%s: illegal option -- %c\n", _getprogname(),
100			    optopt);
101		return (BADCH);
102	}
103
104	/* Does this option need an argument? */
105	if (oli[1] != ':') {
106		/* don't need argument */
107		optarg = NULL;
108		if (*place == 0)
109			++optind;
110	} else {
111		/* Option-argument is either the rest of this argument or the
112		   entire next argument. */
113		if (*place)
114			optarg = place;
115		else if (oli[2] == ':')
116			/*
117			 * GNU Extension, for optional arguments if the rest of
118			 * the argument is empty, we return NULL
119			 */
120			optarg = NULL;
121		else if (nargc > ++optind)
122			optarg = nargv[optind];
123		else {
124			/* option-argument absent */
125			place = EMSG;
126			if (*ostr == ':')
127				return (BADARG);
128			if (opterr)
129				(void)fprintf(stderr,
130				    "%s: option requires an argument -- %c\n",
131				    _getprogname(), optopt);
132			return (BADCH);
133		}
134		place = EMSG;
135		++optind;
136	}
137	return (optopt);			/* return option letter */
138}
139