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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 __KERNEL_RCSID(0, "$NetBSD: subr_optstr.c,v 1.4 2007/02/22 06:34:44 thorpej Exp $"); 41 42 #include <sys/param.h> 43 #include <sys/optstr.h> 44 45 /* --------------------------------------------------------------------- */ 46 47 /* 48 * Given an options string of the form 'a=b c=d ... y=z' and a key, 49 * looks for the given key's value in the string and returns it in buf 50 * with a maximum of bufsize bytes. If the key is found, returns true; 51 * otherwise FALSE. 52 */ 53 bool 54 optstr_get(const char *optstr, const char *key, char *buf, size_t bufsize) 55 { 56 bool found; 57 58 found = false; 59 60 /* Skip any initial spaces until we find a word. */ 61 while (*optstr == ' ' && *optstr != '\0') 62 optstr++; 63 64 /* Search for the given key within the option string. */ 65 while (!found && *optstr != '\0') { 66 const char *keyp; 67 68 /* Check if the next word matches the key. */ 69 keyp = key; 70 while (*optstr == *keyp) { 71 optstr++; 72 keyp++; 73 } 74 75 if (*optstr == '=' && *keyp == '\0') 76 found = true; 77 else { 78 /* Key not found; skip until next space. */ 79 while (*optstr != ' ' && *optstr != '\0') 80 optstr++; 81 82 /* And now skip until next word. */ 83 while (*optstr == ' ' && *optstr != '\0') 84 optstr++; 85 } 86 } 87 88 /* If the key was found; copy its value to the target buffer. */ 89 if (found) { 90 const char *lastbuf; 91 92 lastbuf = buf + (bufsize - 1); 93 94 optstr++; /* Skip '='. */ 95 while (buf != lastbuf && *optstr != ' ' && *optstr != '\0') 96 *buf++ = *optstr++; 97 *buf = '\0'; 98 } 99 100 return found; 101 } 102