xref: /netbsd-src/lib/libc/stdlib/getsubopt.c (revision 73704c4ce4ee2a60eb617e693ce7e9f03902613e)
1 /*	$NetBSD: getsubopt.c,v 1.7 2003/08/07 16:43:40 agc 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 1.7 2003/08/07 16:43:40 agc Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40 
41 #include <assert.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 
46 /*
47  * The SVID interface to getsubopt provides no way of figuring out which
48  * part of the suboptions list wasn't matched.  This makes error messages
49  * tricky...  The extern variable suboptarg is a pointer to the token
50  * which didn't match.
51  */
52 char *suboptarg;
53 
54 int
55 getsubopt(optionp, tokens, valuep)
56 	char **optionp, **valuep;
57 	char * const *tokens;
58 {
59 	int cnt;
60 	char *p;
61 
62 	_DIAGASSERT(valuep != NULL);
63 	_DIAGASSERT(tokens != NULL);
64 	/* optionp is tested below */
65 
66 	suboptarg = *valuep = NULL;
67 
68 	if (!optionp || !*optionp)
69 		return(-1);
70 
71 	/* skip leading white-space, commas */
72 	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
73 
74 	if (!*p) {
75 		*optionp = p;
76 		return(-1);
77 	}
78 
79 	/* save the start of the token, and skip the rest of the token. */
80 	for (suboptarg = p;
81 	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
82 
83 	if (*p) {
84 		/*
85 		 * If there's an equals sign, set the value pointer, and
86 		 * skip over the value part of the token.  Terminate the
87 		 * token.
88 		 */
89 		if (*p == '=') {
90 			*p = '\0';
91 			for (*valuep = ++p;
92 			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
93 			if (*p)
94 				*p++ = '\0';
95 		} else
96 			*p++ = '\0';
97 		/* Skip any whitespace or commas after this token. */
98 		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
99 	}
100 
101 	/* set optionp for next round. */
102 	*optionp = p;
103 
104 	for (cnt = 0; *tokens; ++tokens, ++cnt)
105 		if (!strcmp(suboptarg, *tokens))
106 			return(cnt);
107 	return(-1);
108 }
109