xref: /illumos-gate/usr/src/lib/libc/port/gen/strnlen.c (revision 1da57d55)
1adecd3c6Sdg /*
2adecd3c6Sdg  * CDDL HEADER START
3adecd3c6Sdg  *
4adecd3c6Sdg  * The contents of this file are subject to the terms of the
5adecd3c6Sdg  * Common Development and Distribution License (the "License").
6adecd3c6Sdg  * You may not use this file except in compliance with the License.
7adecd3c6Sdg  *
8adecd3c6Sdg  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9adecd3c6Sdg  * or http://www.opensolaris.org/os/licensing.
10adecd3c6Sdg  * See the License for the specific language governing permissions
11adecd3c6Sdg  * and limitations under the License.
12adecd3c6Sdg  *
13adecd3c6Sdg  * When distributing Covered Code, include this CDDL HEADER in each
14adecd3c6Sdg  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15adecd3c6Sdg  * If applicable, add the following below this CDDL HEADER, with the
16adecd3c6Sdg  * fields enclosed by brackets "[]" replaced with your own identifying
17adecd3c6Sdg  * information: Portions Copyright [yyyy] [name of copyright owner]
18adecd3c6Sdg  *
19adecd3c6Sdg  * CDDL HEADER END
20adecd3c6Sdg  */
21adecd3c6Sdg 
22adecd3c6Sdg /*
23*7257d1b4Sraf  * Copyright 2008 Sun Microsystems, Inc.
24adecd3c6Sdg  * All rights reserved.  Use is subject to license terms.
25adecd3c6Sdg  */
26adecd3c6Sdg 
27*7257d1b4Sraf #include "lint.h"
28adecd3c6Sdg #include <string.h>
29adecd3c6Sdg #include <sys/types.h>
30adecd3c6Sdg 
31adecd3c6Sdg /*
32adecd3c6Sdg  * Returns the number of non-NULL bytes in string argument,
33adecd3c6Sdg  * but not more than maxlen.  Does not look past str + maxlen.
34adecd3c6Sdg  */
35adecd3c6Sdg size_t
strnlen(const char * str,size_t maxlen)36adecd3c6Sdg strnlen(const char *str, size_t maxlen)
37adecd3c6Sdg {
38adecd3c6Sdg 	const char *ptr;
39adecd3c6Sdg 
40adecd3c6Sdg 	ptr = memchr(str, 0, maxlen);
41adecd3c6Sdg 	if (ptr == NULL)
42adecd3c6Sdg 		return (maxlen);
43adecd3c6Sdg 
44adecd3c6Sdg 	return (ptr - str);
45adecd3c6Sdg }
46