xref: /netbsd-src/lib/libc/stdlib/getsubopt.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: getsubopt.c,v 1.8 2004/05/09 19:34:11 kleink Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990, 1993
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 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)getsubopt.c	8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: getsubopt.c,v 1.8 2004/05/09 19:34:11 kleink Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40 
41 #include "namespace.h"
42 
43 #include <assert.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 
48 #ifdef __weak_alias
49 __weak_alias(getsubopt,_getsubopt)
50 #endif
51 
52 /*
53  * The SVID interface to getsubopt provides no way of figuring out which
54  * part of the suboptions list wasn't matched.  This makes error messages
55  * tricky...  The extern variable suboptarg is a pointer to the token
56  * which didn't match.
57  */
58 char *suboptarg;
59 
60 int
61 getsubopt(optionp, tokens, valuep)
62 	char **optionp, **valuep;
63 	char * const *tokens;
64 {
65 	int cnt;
66 	char *p;
67 
68 	_DIAGASSERT(tokens != NULL);
69 	_DIAGASSERT(valuep != NULL);
70 	/* optionp is tested below */
71 
72 	suboptarg = *valuep = NULL;
73 
74 	if (!optionp || !*optionp)
75 		return(-1);
76 
77 	/* skip leading white-space, commas */
78 	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
79 
80 	if (!*p) {
81 		*optionp = p;
82 		return(-1);
83 	}
84 
85 	/* save the start of the token, and skip the rest of the token. */
86 	for (suboptarg = p;
87 	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
88 
89 	if (*p) {
90 		/*
91 		 * If there's an equals sign, set the value pointer, and
92 		 * skip over the value part of the token.  Terminate the
93 		 * token.
94 		 */
95 		if (*p == '=') {
96 			*p = '\0';
97 			for (*valuep = ++p;
98 			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
99 			if (*p)
100 				*p++ = '\0';
101 		} else
102 			*p++ = '\0';
103 		/* Skip any whitespace or commas after this token. */
104 		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
105 	}
106 
107 	/* set optionp for next round. */
108 	*optionp = p;
109 
110 	for (cnt = 0; *tokens; ++tokens, ++cnt)
111 		if (!strcmp(suboptarg, *tokens))
112 			return(cnt);
113 	return(-1);
114 }
115