1/* $NetBSD: subr_optstr.c,v 1.6 2016/05/30 11:24:40 martin 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 1.6 2016/05/30 11:24:40 martin 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 == ' ')
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 == ' ')
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