xref: /illumos-gate/usr/src/lib/libc/port/gen/strncpy.c (revision 7257d1b4)
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.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include "lint.h"
33 #include <string.h>
34 #include <sys/types.h>
35 
36 /*
37  * Copy s2 to s1, truncating or null-padding to always copy n bytes
38  * return s1
39  */
40 char *
strncpy(char * s1,const char * s2,size_t n)41 strncpy(char *s1, const char *s2, size_t n)
42 {
43 	char *os1 = s1;
44 
45 	n++;
46 	while ((--n != 0) && ((*s1++ = *s2++) != '\0'))
47 		;
48 	if (n != 0)
49 		while (--n != 0)
50 			*s1++ = '\0';
51 	return (os1);
52 }
53