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 */ 46 bool 47 optstr_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