xref: /netbsd-src/lib/libc/stdlib/getsubopt.c (revision dc306354b0b29af51801a7632f1e95265a68cd81)
1 /*	$NetBSD: getsubopt.c,v 1.4 1998/02/03 18:44:15 perry 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 #include <sys/cdefs.h>
37 #if defined(LIBC_SCCS) && !defined(lint)
38 #if 0
39 static char sccsid[] = "@(#)getsubopt.c	8.1 (Berkeley) 6/4/93";
40 #else
41 __RCSID("$NetBSD: getsubopt.c,v 1.4 1998/02/03 18:44:15 perry Exp $");
42 #endif
43 #endif /* LIBC_SCCS and not lint */
44 
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 
49 /*
50  * The SVID interface to getsubopt provides no way of figuring out which
51  * part of the suboptions list wasn't matched.  This makes error messages
52  * tricky...  The extern variable suboptarg is a pointer to the token
53  * which didn't match.
54  */
55 char *suboptarg;
56 
57 int
58 getsubopt(optionp, tokens, valuep)
59 	char **optionp, **valuep;
60 	char * const *tokens;
61 {
62 	int cnt;
63 	char *p;
64 
65 	suboptarg = *valuep = NULL;
66 
67 	if (!optionp || !*optionp)
68 		return(-1);
69 
70 	/* skip leading white-space, commas */
71 	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
72 
73 	if (!*p) {
74 		*optionp = p;
75 		return(-1);
76 	}
77 
78 	/* save the start of the token, and skip the rest of the token. */
79 	for (suboptarg = p;
80 	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
81 
82 	if (*p) {
83 		/*
84 		 * If there's an equals sign, set the value pointer, and
85 		 * skip over the value part of the token.  Terminate the
86 		 * token.
87 		 */
88 		if (*p == '=') {
89 			*p = '\0';
90 			for (*valuep = ++p;
91 			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
92 			if (*p)
93 				*p++ = '\0';
94 		} else
95 			*p++ = '\0';
96 		/* Skip any whitespace or commas after this token. */
97 		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
98 	}
99 
100 	/* set optionp for next round. */
101 	*optionp = p;
102 
103 	for (cnt = 0; *tokens; ++tokens, ++cnt)
104 		if (!strcmp(suboptarg, *tokens))
105 			return(cnt);
106 	return(-1);
107 }
108