xref: /freebsd/lib/libc/stdlib/getsubopt.c (revision 8fb3f3f68288ae2b1b53dd65e3dd673d83c80f4c)
1 /*-
2  * Copyright (c) 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)getsubopt.c	8.1 (Berkeley) 6/4/93";
36 #endif /* LIBC_SCCS and not lint */
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <unistd.h>
41 #include <stdlib.h>
42 
43 /*
44  * The SVID interface to getsubopt provides no way of figuring out which
45  * part of the suboptions list wasn't matched.  This makes error messages
46  * tricky...  The extern variable suboptarg is a pointer to the token
47  * which didn't match.
48  */
49 char *suboptarg;
50 
51 int
52 getsubopt(optionp, tokens, valuep)
53 	char **optionp, **valuep;
54 	char * const *tokens;
55 {
56 	int cnt;
57 	char *p;
58 
59 	suboptarg = *valuep = NULL;
60 
61 	if (!optionp || !*optionp)
62 		return(-1);
63 
64 	/* skip leading white-space, commas */
65 	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
66 
67 	if (!*p) {
68 		*optionp = p;
69 		return(-1);
70 	}
71 
72 	/* save the start of the token, and skip the rest of the token. */
73 	for (suboptarg = p;
74 	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
75 
76 	if (*p) {
77 		/*
78 		 * If there's an equals sign, set the value pointer, and
79 		 * skip over the value part of the token.  Terminate the
80 		 * token.
81 		 */
82 		if (*p == '=') {
83 			*p = '\0';
84 			for (*valuep = ++p;
85 			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
86 			if (*p)
87 				*p++ = '\0';
88 		} else
89 			*p++ = '\0';
90 		/* Skip any whitespace or commas after this token. */
91 		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
92 	}
93 
94 	/* set optionp for next round. */
95 	*optionp = p;
96 
97 	for (cnt = 0; *tokens; ++tokens, ++cnt)
98 		if (!strcmp(suboptarg, *tokens))
99 			return(cnt);
100 	return(-1);
101 }
102