xref: /freebsd/lib/libc/stdlib/getopt.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
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 #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 
47 int	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 */
51 char	*optarg;		/* argument associated with option */
52 
53 #define	BADCH	(int)'?'
54 #define	BADARG	(int)':'
55 static char EMSG[] = "";
56 /*
57  * getopt --
58  *	Parse argc/argv argument vector.
59  */
60 int
61 getopt(int nargc, char * const nargv[], const char *ostr)
62 {
63 	static char *place = EMSG;		/* option letter processing */
64 	char *oli;				/* option letter list index */
65 
66 	if (optreset || *place == 0) {		/* update scanning pointer */
67 		optreset = 0;
68 		place = nargv[optind];
69 		if (optind >= nargc || *place++ != '-') {
70 			/* Argument is absent or is not an option */
71 			place = EMSG;
72 			return (-1);
73 		}
74 		optopt = *place++;
75 		if (optopt == '-' && *place == 0) {
76 			/* "--" => end of options */
77 			++optind;
78 			place = EMSG;
79 			return (-1);
80 		}
81 		if (optopt == 0) {
82 			/* Solitary '-', treat as a '-' option
83 			   if the program (eg su) is looking for it. */
84 			place = EMSG;
85 			if (strchr(ostr, '-') == NULL)
86 				return (-1);
87 			optopt = '-';
88 		}
89 	} else
90 		optopt = *place++;
91 
92 	/* See if option letter is one the caller wanted... */
93 	if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
94 		if (*place == 0)
95 			++optind;
96 		if (opterr && *ostr != ':')
97 			(void)fprintf(stderr,
98 			    "%s: illegal option -- %c\n", _getprogname(),
99 			    optopt);
100 		return (BADCH);
101 	}
102 
103 	/* Does this option need an argument? */
104 	if (oli[1] != ':') {
105 		/* don't need argument */
106 		optarg = NULL;
107 		if (*place == 0)
108 			++optind;
109 	} else {
110 		/* Option-argument is either the rest of this argument or the
111 		   entire next argument. */
112 		if (*place)
113 			optarg = place;
114 		else if (oli[2] == ':')
115 			/*
116 			 * GNU Extension, for optional arguments if the rest of
117 			 * the argument is empty, we return NULL
118 			 */
119 			optarg = NULL;
120 		else if (nargc > ++optind)
121 			optarg = nargv[optind];
122 		else {
123 			/* option-argument absent */
124 			place = EMSG;
125 			if (*ostr == ':')
126 				return (BADARG);
127 			if (opterr)
128 				(void)fprintf(stderr,
129 				    "%s: option requires an argument -- %c\n",
130 				    _getprogname(), optopt);
131 			return (BADCH);
132 		}
133 		place = EMSG;
134 		++optind;
135 	}
136 	return (optopt);			/* return option letter */
137 }
138