xref: /netbsd-src/lib/libc/stdlib/getsubopt.c (revision 48875230b6c3331b32b9c7bfc518969d58c388e0)
1 /*	$NetBSD: getsubopt.c,v 1.10 2018/08/30 12:06:06 christos 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 #if HAVE_NBTOOL_CONFIG_H
33 #include "nbtool_config.h"
34 #endif
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 1.10 2018/08/30 12:06:06 christos Exp $");
42 #endif
43 #endif /* LIBC_SCCS and not lint */
44 
45 #include "namespace.h"
46 
47 #include <assert.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 
52 #ifdef __weak_alias
__weak_alias(getsubopt,_getsubopt)53 __weak_alias(getsubopt,_getsubopt)
54 #endif
55 
56 /*
57  * The SVID interface to getsubopt provides no way of figuring out which
58  * part of the suboptions list wasn't matched.  This makes error messages
59  * tricky...  The extern variable suboptarg is a pointer to the token
60  * which didn't match.
61  */
62 char *suboptarg;
63 
64 int
65 getsubopt(char **optionp, char * const *tokens, char **valuep)
66 {
67 	int cnt;
68 	char *p;
69 
70 	_DIAGASSERT(tokens != NULL);
71 	_DIAGASSERT(valuep != NULL);
72 	/* optionp is tested below */
73 
74 	suboptarg = *valuep = NULL;
75 
76 	if (!optionp || !*optionp)
77 		return(-1);
78 
79 	/* skip leading white-space, commas */
80 	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
81 
82 	if (!*p) {
83 		*optionp = p;
84 		return(-1);
85 	}
86 
87 	/* save the start of the token, and skip the rest of the token. */
88 	for (suboptarg = p;
89 	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
90 
91 	if (*p) {
92 		/*
93 		 * If there's an equals sign, set the value pointer, and
94 		 * skip over the value part of the token.  Terminate the
95 		 * token.
96 		 */
97 		if (*p == '=') {
98 			*p = '\0';
99 			for (*valuep = ++p;
100 			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
101 			if (*p)
102 				*p++ = '\0';
103 		} else
104 			*p++ = '\0';
105 		/* Skip any whitespace or commas after this token. */
106 		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
107 	}
108 
109 	/* set optionp for next round. */
110 	*optionp = p;
111 
112 	for (cnt = 0; *tokens; ++tokens, ++cnt)
113 		if (!strcmp(suboptarg, *tokens))
114 			return(cnt);
115 	return(-1);
116 }
117