lib/libspl/strnlen.c

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