xref: /illumos-gate/usr/src/lib/libc/port/gen/strndup.c (revision 159a0043473914c03b72d9f0c70c5aae42493748)
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 (c) 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright 2018 Joyent, Inc.
25  */
26 
27 #include "lint.h"
28 #include <string.h>
29 #include <strings.h>
30 #include <stdlib.h>
31 #include <sys/types.h>
32 
33 /*
34  * Create a copy of string s, but only duplicate the first n bytes.
35  * Return NULL if the new string can't be allocated.
36  */
37 char *
strndup(const char * s1,size_t n)38 strndup(const char *s1, size_t n)
39 {
40 	char *s2;
41 
42 	n = strnlen(s1, n);
43 	if ((s2 = malloc(n + 1)) != NULL) {
44 		bcopy(s1, s2, n);
45 		s2[n] = '\0';
46 	}
47 
48 	return (s2);
49 }
50