xref: /freebsd/lib/libc/stdlib/getopt.c (revision 1ca63a8219b88b752b064d19bd3428c61dbcf1f9)
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 "namespace.h"
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 #include "un-namespace.h"
43 
44 #include "libc_private.h"
45 
46 int	opterr = 1,		/* if error message should be printed */
47 	optind = 1,		/* index into parent argv vector */
48 	optopt,			/* character checked for validity */
49 	optreset;		/* reset getopt */
50 char	*optarg;		/* argument associated with option */
51 
52 #define	BADCH	(int)'?'
53 #define	BADARG	(int)':'
54 static char EMSG[] = "";
55 /*
56  * getopt --
57  *	Parse argc/argv argument vector.
58  */
59 int
60 getopt(int nargc, char * const nargv[], const char *ostr)
61 {
62 	static char *place = EMSG;		/* option letter processing */
63 	char *oli;				/* option letter list index */
64 
65 	if (optreset || *place == 0) {		/* update scanning pointer */
66 		optreset = 0;
67 		place = nargv[optind];
68 		if (optind >= nargc || *place++ != '-') {
69 			/* Argument is absent or is not an option */
70 			place = EMSG;
71 			return (-1);
72 		}
73 		optopt = *place++;
74 		if (optopt == '-' && *place == 0) {
75 			/* "--" => end of options */
76 			++optind;
77 			place = EMSG;
78 			return (-1);
79 		}
80 		if (optopt == 0) {
81 			/* Solitary '-', treat as a '-' option
82 			   if the program (eg su) is looking for it. */
83 			place = EMSG;
84 			if (strchr(ostr, '-') == NULL)
85 				return (-1);
86 			optopt = '-';
87 		}
88 	} else
89 		optopt = *place++;
90 
91 	/* See if option letter is one the caller wanted... */
92 	if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
93 		if (*place == 0)
94 			++optind;
95 		if (opterr && *ostr != ':')
96 			(void)fprintf(stderr,
97 			    "%s: illegal option -- %c\n", _getprogname(),
98 			    optopt);
99 		return (BADCH);
100 	}
101 
102 	/* Does this option need an argument? */
103 	if (oli[1] != ':') {
104 		/* don't need argument */
105 		optarg = NULL;
106 		if (*place == 0)
107 			++optind;
108 	} else {
109 		/* Option-argument is either the rest of this argument or the
110 		   entire next argument. */
111 		if (*place)
112 			optarg = place;
113 		else if (oli[2] == ':')
114 			/*
115 			 * GNU Extension, for optional arguments if the rest of
116 			 * the argument is empty, we return NULL
117 			 */
118 			optarg = NULL;
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