NetBSD/sys/kern/subr_optstr.c

95 lines
3.0 KiB
C

/* $NetBSD: subr_optstr.c,v 1.6 2016/05/30 11:24:40 martin 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.
*
* 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 1.6 2016/05/30 11:24:40 martin 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.
*/
bool
optstr_get(const char *optstr, const char *key, char *buf, size_t bufsize)
{
bool found;
found = false;
/* Skip any initial spaces until we find a word. */
while (*optstr == ' ')
optstr++;
/* Search for the given key within the option string. */
while (!found && *optstr != '\0') {
const char *keyp;
/* Check if the next word matches the key. */
keyp = key;
while (*optstr == *keyp) {
optstr++;
keyp++;
}
if (*optstr == '=' && *keyp == '\0')
found = true;
else {
/* Key not found; skip until next space. */
while (*optstr != ' ' && *optstr != '\0')
optstr++;
/* And now skip until next word. */
while (*optstr == ' ')
optstr++;
}
}
/* If the key was found; copy its value to the target buffer. */
if (found) {
const char *lastbuf;
lastbuf = buf + (bufsize - 1);
optstr++; /* Skip '='. */
while (buf != lastbuf && *optstr != ' ' && *optstr != '\0')
*buf++ = *optstr++;
*buf = '\0';
}
return found;
}