NetBSD/sys/kern/subr_optstr.c
jmmv 47d8ee4167 Implement options string parsing of the form 'a=b c=d ...'. This will be
initially used by i386's Multiboot support but will be useful in other
situations too (think refactoring mount(2)'s API).
2006-02-03 11:04:46 +00:00

102 lines
3.4 KiB
C

/* $NetBSD: subr_optstr.c,v 1.1 2006/02/03 11:04:46 jmmv Exp $ */
/*-
* Copyright (c) 2006 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Julio M. Merino Vidal.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: subr_optstr.c,v 1.1 2006/02/03 11:04:46 jmmv Exp $");
#include <sys/param.h>
#include <sys/optstr.h>
/* --------------------------------------------------------------------- */
/*
* Given an options string of the form 'a=b c=d ... y=z' and a key,
* looks for the given key's value in the string and returns it in buf
* with a maximum of bufsize bytes. If the key is found, returns TRUE;
* otherwise FALSE.
*/
boolean_t
optstr_get(const char *optstr, const char *key, char *buf, size_t bufsize)
{
boolean_t found;
const char *keyp;
found = FALSE;
/* Skip any initial spaces until we find a word. */
while (*optstr == ' ' && *optstr != '\0')
optstr++;
/* Search for the given key within the option string. */
while (!found && *optstr != '\0') {
/* Check if the next word matches the key. */
keyp = key;
while (*optstr == *keyp) {
optstr++;
keyp++;
}
if (*optstr == '=')
found = TRUE;
else {
/* Key not found; skip until next space. */
while (*optstr != ' ' && *optstr != '\0')
optstr++;
/* And now skip until next word. */
while (*optstr == ' ' && *optstr != '\0')
optstr++;
}
}
/* If the key was found; copy its value to the target buffer. */
if (found) {
const char *lastbuf;
lastbuf = buf + (bufsize - 1);
found = TRUE;
optstr++; /* Skip '='. */
while (buf != lastbuf && *optstr != ' ' && *optstr != '\0')
*buf++ = *optstr++;
*buf = '\0';
}
return found;
}