xref: /freebsd/lib/libc/stdlib/getsubopt.c (revision 3ecbeb2d3a662b51fab68e66652309dd59e6d38c)
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 <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43 
44 /*
45  * The SVID interface to getsubopt provides no way of figuring out which
46  * part of the suboptions list wasn't matched.  This makes error messages
47  * tricky...  The extern variable suboptarg is a pointer to the token
48  * which didn't match.
49  */
50 char *suboptarg;
51 
52 int
53 getsubopt(optionp, tokens, valuep)
54 	char **optionp, **valuep;
55 	char * const *tokens;
56 {
57 	int cnt;
58 	char *p;
59 
60 	suboptarg = *valuep = NULL;
61 
62 	if (!optionp || !*optionp)
63 		return(-1);
64 
65 	/* skip leading white-space, commas */
66 	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
67 
68 	if (!*p) {
69 		*optionp = p;
70 		return(-1);
71 	}
72 
73 	/* save the start of the token, and skip the rest of the token. */
74 	for (suboptarg = p;
75 	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
76 
77 	if (*p) {
78 		/*
79 		 * If there's an equals sign, set the value pointer, and
80 		 * skip over the value part of the token.  Terminate the
81 		 * token.
82 		 */
83 		if (*p == '=') {
84 			*p = '\0';
85 			for (*valuep = ++p;
86 			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
87 			if (*p)
88 				*p++ = '\0';
89 		} else
90 			*p++ = '\0';
91 		/* Skip any whitespace or commas after this token. */
92 		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
93 	}
94 
95 	/* set optionp for next round. */
96 	*optionp = p;
97 
98 	for (cnt = 0; *tokens; ++tokens, ++cnt)
99 		if (!strcmp(suboptarg, *tokens))
100 			return(cnt);
101 	return(-1);
102 }
103