xref: /illumos-gate/usr/src/common/util/memchr.c (revision 7c478bd9)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*	Copyright (c) 1988 AT&T	*/
30 /*	  All Rights Reserved  	*/
31 
32 
33 #include <sys/types.h>
34 #if defined(_KERNEL)
35 #include <sys/systm.h>
36 #else
37 #include <string.h>
38 #include <stddef.h>
39 #endif
40 
41 /*
42  * Return the ptr in sptr at which the character c1 appears;
43  * or NULL if not found in n chars; don't stop at \0.
44  */
45 void *
memchr(const void * sptr,int c1,size_t n)46 memchr(const void *sptr, int c1, size_t n)
47 {
48 	if (n != 0) {
49 		unsigned char c = (unsigned char)c1;
50 		const unsigned char *sp = sptr;
51 
52 		do {
53 			if (*sp++ == c)
54 				return ((void *)--sp);
55 		} while (--n != 0);
56 	}
57 	return (NULL);
58 }
59