1/*	$NetBSD: subr_optstr.c,v 1.4 2007/02/22 06:34:44 thorpej Exp $	*/
2
3/*-
4 * Copyright (c) 2006 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Julio M. Merino Vidal.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__KERNEL_RCSID(0, "$NetBSD: subr_optstr.c,v 1.4 2007/02/22 06:34:44 thorpej Exp $");
34
35#include <sys/param.h>
36#include <sys/optstr.h>
37
38/* --------------------------------------------------------------------- */
39
40/*
41 * Given an options string of the form 'a=b c=d ... y=z' and a key,
42 * looks for the given key's value in the string and returns it in buf
43 * with a maximum of bufsize bytes.  If the key is found, returns true;
44 * otherwise FALSE.
45 */
46bool
47optstr_get(const char *optstr, const char *key, char *buf, size_t bufsize)
48{
49	bool found;
50
51	found = false;
52
53	/* Skip any initial spaces until we find a word. */
54	while (*optstr == ' ' && *optstr != '\0')
55		optstr++;
56
57	/* Search for the given key within the option string. */
58	while (!found && *optstr != '\0') {
59		const char *keyp;
60
61		/* Check if the next word matches the key. */
62		keyp = key;
63		while (*optstr == *keyp) {
64			optstr++;
65			keyp++;
66		}
67
68		if (*optstr == '=' && *keyp == '\0')
69			found = true;
70		else {
71			/* Key not found; skip until next space. */
72			while (*optstr != ' ' && *optstr != '\0')
73				optstr++;
74
75			/* And now skip until next word. */
76			while (*optstr == ' ' && *optstr != '\0')
77				optstr++;
78		}
79	}
80
81	/* If the key was found; copy its value to the target buffer. */
82	if (found) {
83		const char *lastbuf;
84
85		lastbuf = buf + (bufsize - 1);
86
87		optstr++; /* Skip '='. */
88		while (buf != lastbuf && *optstr != ' ' && *optstr != '\0')
89			*buf++ = *optstr++;
90		*buf = '\0';
91	}
92
93	return found;
94}
95