xref: /illumos-gate/usr/src/lib/libc/port/gen/strncat.c (revision 1da57d551424de5a9d469760be7c4b4d4f10a755)
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 #include "lint.h"
31 #include <string.h>
32 #include <sys/types.h>
33 
34 /*
35  * Concatenate s2 on the end of s1.  S1's space must be large enough.
36  * At most n characters are moved.
37  * Return s1.
38  */
39 char *
strncat(char * s1,const char * s2,size_t n)40 strncat(char *s1, const char *s2, size_t n)
41 {
42 	char *os1 = s1;
43 
44 	n++;
45 	while (*s1++)
46 		;
47 	--s1;
48 	while (*s1++ = *s2++)
49 		if (--n == 0) {
50 			s1[-1] = '\0';
51 			break;
52 		}
53 	return (os1);
54 }
55