zfs/lib/libspl/include/string.h

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#ifndef _LIBSPL_STRING_H
#define	_LIBSPL_STRING_H

#include_next <string.h>
#include <sys/types.h>

/*
 * Appends src to the dstsize buffer at dst. The append will never
 * overflow the destination buffer and the buffer will always be null
 * terminated. Never reference beyond &dst[dstsize-1] when computing
 * the length of the pre-existing string.
 */
static inline size_t
strlcat(char *dst, const char *src, size_t dstsize)
{
	char *df = dst;
	size_t left = dstsize;
	size_t l1;
	size_t l2 = strlen(src);
	size_t copied;

	while (left-- != 0 && *df != '\0')
		df++;

	l1 = df - dst;

	if (dstsize == l1)
		return (l1 + l2);

	copied = l1 + l2 >= dstsize ? dstsize - l1 - 1 : l2;
	(void) memcpy(dst + l1, src, copied);
	dst[l1+copied] = '\0';

	return (l1 + l2);
}

/*
 * Copies src to the dstsize buffer at dst. The copy will never
 * overflow the destination buffer and the buffer will always be null
 * terminated.
 */
static inline size_t
strlcpy(char *dst, const char *src, size_t len)
{
	size_t slen = strlen(src);

	if (len == 0)
		return (slen);

	size_t copied = (slen >= len) ? len - 1 : slen;
	(void) memcpy(dst, src, copied);
	dst[copied] = '\0';

	return (slen);
}

#endif