zfs/lib/libspl/strnlen.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.
 * All rights reserved.  Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#include <string.h>

/*
 * Returns the number of non-NULL bytes in string argument,
 * but not more than maxlen.  Does not look past str + maxlen.
 */
size_t
strnlen(const char *str, size_t maxlen)
{
	const char *ptr;

	ptr = memchr(str, 0, maxlen);
	if (ptr == NULL)
		return (maxlen);

	return (ptr - str);
}