xref: /freebsd/lib/libc/stdlib/getopt.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
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 #define	EMSG	""
58 
59 /*
60  * getopt --
61  *	Parse argc/argv argument vector.
62  */
63 int
64 getopt(int nargc, char * const nargv[], const char *ostr)
65 {
66 	static char *place = EMSG;		/* option letter processing */
67 	char *oli;				/* option letter list index */
68 
69 	if (optreset || *place == 0) {		/* update scanning pointer */
70 		optreset = 0;
71 		place = nargv[optind];
72 		if (optind >= nargc || *place++ != '-') {
73 			/* Argument is absent or is not an option */
74 			place = EMSG;
75 			return (-1);
76 		}
77 		optopt = *place++;
78 		if (optopt == '-' && *place == 0) {
79 			/* "--" => end of options */
80 			++optind;
81 			place = EMSG;
82 			return (-1);
83 		}
84 		if (optopt == 0) {
85 			/* Solitary '-', treat as a '-' option
86 			   if the program (eg su) is looking for it. */
87 			place = EMSG;
88 			if (strchr(ostr, '-') == NULL)
89 				return (-1);
90 			optopt = '-';
91 		}
92 	} else
93 		optopt = *place++;
94 
95 	/* See if option letter is one the caller wanted... */
96 	if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
97 		if (*place == 0)
98 			++optind;
99 		if (opterr && *ostr != ':')
100 			(void)fprintf(stderr,
101 			    "%s: illegal option -- %c\n", _getprogname(),
102 			    optopt);
103 		return (BADCH);
104 	}
105 
106 	/* Does this option need an argument? */
107 	if (oli[1] != ':') {
108 		/* don't need argument */
109 		optarg = NULL;
110 		if (*place == 0)
111 			++optind;
112 	} else {
113 		/* Option-argument is either the rest of this argument or the
114 		   entire next argument. */
115 		if (*place)
116 			optarg = place;
117 		else if (oli[2] == ':')
118 			/*
119 			 * GNU Extension, for optional arguments if the rest of
120 			 * the argument is empty, we return NULL
121 			 */
122 			optarg = NULL;
123 		else if (nargc > ++optind)
124 			optarg = nargv[optind];
125 		else {
126 			/* option-argument absent */
127 			place = EMSG;
128 			if (*ostr == ':')
129 				return (BADARG);
130 			if (opterr)
131 				(void)fprintf(stderr,
132 				    "%s: option requires an argument -- %c\n",
133 				    _getprogname(), optopt);
134 			return (BADCH);
135 		}
136 		place = EMSG;
137 		++optind;
138 	}
139 	return (optopt);			/* return option letter */
140 }
141