xref: /openbsd-src/lib/libc/stdlib/getsubopt.c (revision b725ae7711052a2233e31a66fefb8a752c388d7a)
1 /*	$OpenBSD: getsubopt.c,v 1.2 2003/06/02 20:18:37 millert 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 #ifndef lint
33 #if 0
34 static char sccsid[] = "@(#)getsubopt.c	8.1 (Berkeley) 6/4/93";
35 #else
36 static char rcsid[] = "$OpenBSD: getsubopt.c,v 1.2 2003/06/02 20:18:37 millert Exp $";
37 #endif
38 #endif /* not lint */
39 
40 #include <unistd.h>
41 #include <stdlib.h>
42 #include <string.h>
43 
44 /*
45  * The SVID interface to getsubopt provides no way of figuring out which
46  * part of the suboptions list wasn't matched.  This makes error messages
47  * tricky...  The extern variable suboptarg is a pointer to the token
48  * which didn't match.
49  */
50 char *suboptarg;
51 
52 int
53 getsubopt(optionp, tokens, valuep)
54 	register char **optionp, **valuep;
55 	register char * const *tokens;
56 {
57 	register int cnt;
58 	register char *p;
59 
60 	suboptarg = *valuep = NULL;
61 
62 	if (!optionp || !*optionp)
63 		return(-1);
64 
65 	/* skip leading white-space, commas */
66 	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
67 
68 	if (!*p) {
69 		*optionp = p;
70 		return(-1);
71 	}
72 
73 	/* save the start of the token, and skip the rest of the token. */
74 	for (suboptarg = p;
75 	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
76 
77 	if (*p) {
78 		/*
79 		 * If there's an equals sign, set the value pointer, and
80 		 * skip over the value part of the token.  Terminate the
81 		 * token.
82 		 */
83 		if (*p == '=') {
84 			*p = '\0';
85 			for (*valuep = ++p;
86 			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
87 			if (*p)
88 				*p++ = '\0';
89 		} else
90 			*p++ = '\0';
91 		/* Skip any whitespace or commas after this token. */
92 		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
93 	}
94 
95 	/* set optionp for next round. */
96 	*optionp = p;
97 
98 	for (cnt = 0; *tokens; ++tokens, ++cnt)
99 		if (!strcmp(suboptarg, *tokens))
100 			return(cnt);
101 	return(-1);
102 }
103