1 /*	$OpenBSD: getsubopt.c,v 1.4 2005/08/08 08:05:36 espie 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 #include <unistd.h>
33 #include <stdlib.h>
34 #include <string.h>
35 
36 /*
37  * The SVID interface to getsubopt provides no way of figuring out which
38  * part of the suboptions list wasn't matched.  This makes error messages
39  * tricky...  The extern variable suboptarg is a pointer to the token
40  * which didn't match.
41  */
42 char *suboptarg;
43 
44 int
getsubopt(char ** optionp,char * const * tokens,char ** valuep)45 getsubopt(char **optionp, char * const *tokens, char **valuep)
46 {
47 	int cnt;
48 	char *p;
49 
50 	suboptarg = *valuep = NULL;
51 
52 	if (!optionp || !*optionp)
53 		return(-1);
54 
55 	/* skip leading white-space, commas */
56 	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
57 
58 	if (!*p) {
59 		*optionp = p;
60 		return(-1);
61 	}
62 
63 	/* save the start of the token, and skip the rest of the token. */
64 	for (suboptarg = p;
65 	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
66 
67 	if (*p) {
68 		/*
69 		 * If there's an equals sign, set the value pointer, and
70 		 * skip over the value part of the token.  Terminate the
71 		 * token.
72 		 */
73 		if (*p == '=') {
74 			*p = '\0';
75 			for (*valuep = ++p;
76 			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
77 			if (*p)
78 				*p++ = '\0';
79 		} else
80 			*p++ = '\0';
81 		/* Skip any whitespace or commas after this token. */
82 		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
83 	}
84 
85 	/* set optionp for next round. */
86 	*optionp = p;
87 
88 	for (cnt = 0; *tokens; ++tokens, ++cnt)
89 		if (!strcmp(suboptarg, *tokens))
90 			return(cnt);
91 	return(-1);
92 }
93