xref: /openbsd-src/lib/libc/stdlib/getsubopt.c (revision 62a742911104f98b9185b2c6b6007d9b1c36396c)
1 /*	$OpenBSD: getsubopt.c,v 1.1 1997/08/20 04:02:17 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)getsubopt.c	8.1 (Berkeley) 6/4/93";
39 #else
40 static char rcsid[] = "$OpenBSD: getsubopt.c,v 1.1 1997/08/20 04:02:17 millert Exp $";
41 #endif
42 #endif /* not lint */
43 
44 #include <unistd.h>
45 #include <stdlib.h>
46 #include <string.h>
47 
48 /*
49  * The SVID interface to getsubopt provides no way of figuring out which
50  * part of the suboptions list wasn't matched.  This makes error messages
51  * tricky...  The extern variable suboptarg is a pointer to the token
52  * which didn't match.
53  */
54 char *suboptarg;
55 
56 int
57 getsubopt(optionp, tokens, valuep)
58 	register char **optionp, **valuep;
59 	register char * const *tokens;
60 {
61 	register int cnt;
62 	register char *p;
63 
64 	suboptarg = *valuep = NULL;
65 
66 	if (!optionp || !*optionp)
67 		return(-1);
68 
69 	/* skip leading white-space, commas */
70 	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
71 
72 	if (!*p) {
73 		*optionp = p;
74 		return(-1);
75 	}
76 
77 	/* save the start of the token, and skip the rest of the token. */
78 	for (suboptarg = p;
79 	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
80 
81 	if (*p) {
82 		/*
83 		 * If there's an equals sign, set the value pointer, and
84 		 * skip over the value part of the token.  Terminate the
85 		 * token.
86 		 */
87 		if (*p == '=') {
88 			*p = '\0';
89 			for (*valuep = ++p;
90 			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
91 			if (*p)
92 				*p++ = '\0';
93 		} else
94 			*p++ = '\0';
95 		/* Skip any whitespace or commas after this token. */
96 		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
97 	}
98 
99 	/* set optionp for next round. */
100 	*optionp = p;
101 
102 	for (cnt = 0; *tokens; ++tokens, ++cnt)
103 		if (!strcmp(suboptarg, *tokens))
104 			return(cnt);
105 	return(-1);
106 }
107