xref: /freebsd/lib/libc/stdlib/getsubopt.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)getsubopt.c	8.1 (Berkeley) 6/4/93";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <stdlib.h>
37 #include <string.h>
38 
39 /*
40  * The SVID interface to getsubopt provides no way of figuring out which
41  * part of the suboptions list wasn't matched.  This makes error messages
42  * tricky...  The extern variable suboptarg is a pointer to the token
43  * which didn't match.
44  */
45 char *suboptarg;
46 
47 int
48 getsubopt(optionp, tokens, valuep)
49 	char **optionp, **valuep;
50 	char * const *tokens;
51 {
52 	int cnt;
53 	char *p;
54 
55 	suboptarg = *valuep = NULL;
56 
57 	if (!optionp || !*optionp)
58 		return(-1);
59 
60 	/* skip leading white-space, commas */
61 	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
62 
63 	if (!*p) {
64 		*optionp = p;
65 		return(-1);
66 	}
67 
68 	/* save the start of the token, and skip the rest of the token. */
69 	for (suboptarg = p;
70 	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
71 
72 	if (*p) {
73 		/*
74 		 * If there's an equals sign, set the value pointer, and
75 		 * skip over the value part of the token.  Terminate the
76 		 * token.
77 		 */
78 		if (*p == '=') {
79 			*p = '\0';
80 			for (*valuep = ++p;
81 			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
82 			if (*p)
83 				*p++ = '\0';
84 		} else
85 			*p++ = '\0';
86 		/* Skip any whitespace or commas after this token. */
87 		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
88 	}
89 
90 	/* set optionp for next round. */
91 	*optionp = p;
92 
93 	for (cnt = 0; *tokens; ++tokens, ++cnt)
94 		if (!strcmp(suboptarg, *tokens))
95 			return(cnt);
96 	return(-1);
97 }
98