xref: /freebsd/lib/libc/stdlib/getopt.c (revision cab6a39d7b343596a5823e65c0f7b426551ec22d)
1 /*	$NetBSD: getopt.c,v 1.29 2014/06/05 22:00:22 christos Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-3-Clause
5  *
6  * Copyright (c) 1987, 1993, 1994
7  *	The Regents of the University of California.  All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)getopt.c	8.3 (Berkeley) 4/27/95";
36 #endif /* LIBC_SCCS and not lint */
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include "namespace.h"
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 #include "un-namespace.h"
46 
47 #include "libc_private.h"
48 
49 int	opterr = 1,		/* if error message should be printed */
50 	optind = 1,		/* index into parent argv vector */
51 	optopt,			/* character checked for validity */
52 	optreset;		/* reset getopt */
53 char	*optarg;		/* argument associated with option */
54 
55 #define	BADCH	(int)'?'
56 #define	BADARG	(int)':'
57 static char EMSG[] = "";
58 /*
59  * getopt --
60  *	Parse argc/argv argument vector.
61  */
62 int
63 getopt(int nargc, char * const nargv[], const char *ostr)
64 {
65 	static char *place = EMSG;		/* option letter processing */
66 	char *oli;				/* option letter list index */
67 
68 	if (optreset || *place == 0) {		/* update scanning pointer */
69 		optreset = 0;
70 		place = nargv[optind];
71 		if (optind >= nargc || *place++ != '-') {
72 			/* Argument is absent or is not an option */
73 			place = EMSG;
74 			return (-1);
75 		}
76 		optopt = *place++;
77 		if (optopt == '-' && *place == 0) {
78 			/* "--" => end of options */
79 			++optind;
80 			place = EMSG;
81 			return (-1);
82 		}
83 		if (optopt == 0) {
84 			/* Solitary '-', treat as a '-' option
85 			   if the program (eg su) is looking for it. */
86 			place = EMSG;
87 			if (strchr(ostr, '-') == NULL)
88 				return (-1);
89 			optopt = '-';
90 		}
91 	} else
92 		optopt = *place++;
93 
94 	/* See if option letter is one the caller wanted... */
95 	if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
96 		if (*place == 0)
97 			++optind;
98 		if (opterr && *ostr != ':')
99 			(void)fprintf(stderr,
100 			    "%s: illegal option -- %c\n", _getprogname(),
101 			    optopt);
102 		return (BADCH);
103 	}
104 
105 	/* Does this option need an argument? */
106 	if (oli[1] != ':') {
107 		/* don't need argument */
108 		optarg = NULL;
109 		if (*place == 0)
110 			++optind;
111 	} else {
112 		/* Option-argument is either the rest of this argument or the
113 		   entire next argument. */
114 		if (*place)
115 			optarg = place;
116 		else if (oli[2] == ':')
117 			/*
118 			 * GNU Extension, for optional arguments if the rest of
119 			 * the argument is empty, we return NULL
120 			 */
121 			optarg = NULL;
122 		else if (nargc > ++optind)
123 			optarg = nargv[optind];
124 		else {
125 			/* option-argument absent */
126 			place = EMSG;
127 			if (*ostr == ':')
128 				return (BADARG);
129 			if (opterr)
130 				(void)fprintf(stderr,
131 				    "%s: option requires an argument -- %c\n",
132 				    _getprogname(), optopt);
133 			return (BADCH);
134 		}
135 		place = EMSG;
136 		++optind;
137 	}
138 	return (optopt);			/* return option letter */
139 }
140