xref: /titanic_51/usr/src/lib/libc/port/gen/strncpy.c (revision 275c9da86e89f8abf71135cf63d9fc23671b2e60)
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 "synonyms.h"
34 #include <string.h>
35 #include <sys/types.h>
36 
37 /*
38  * Copy s2 to s1, truncating or null-padding to always copy n bytes
39  * return s1
40  */
41 char *
42 strncpy(char *s1, const char *s2, size_t n)
43 {
44 	char *os1 = s1;
45 
46 	n++;
47 	while ((--n != 0) && ((*s1++ = *s2++) != '\0'))
48 		;
49 	if (n != 0)
50 		while (--n != 0)
51 			*s1++ = '\0';
52 	return (os1);
53 }
54