1  /*      $NetBSD: strndup.c,v 1.3 2007/01/14 23:41:24 cbiere Exp $       */
 2  
 3  /*
 4   * Copyright (c) 1988, 1993
 5   *	The Regents of the University of California.  All rights reserved.
 6   *
 7   * Redistribution and use in source and binary forms, with or without
 8   * modification, are permitted provided that the following conditions
 9   * are met:
10   * 1. Redistributions of source code must retain the above copyright
11   *    notice, this list of conditions and the following disclaimer.
12   * 2. Redistributions in binary form must reproduce the above copyright
13   *    notice, this list of conditions and the following disclaimer in the
14   *    documentation and/or other materials provided with the distribution.
15   * 4. Neither the name of the University nor the names of its contributors
16   *    may be used to endorse or promote products derived from this software
17   *    without specific prior written permission.
18   *
19   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29   * SUCH DAMAGE.
30   */
31  
32  #include <sys/cdefs.h>
33  __FBSDID("$FreeBSD: src/lib/libc/string/strndup.c,v 1.1 2008/12/06 09:37:54 kib Exp $");
34  
35  #include <stddef.h>
36  #include <stdlib.h>
37  #include <string.h>
38  
39  char *
40  strndup(const char *str, size_t n)
41  {
42  	size_t len;
43  	char *copy;
44  
45  	for (len = 0; len < n && str[len]; len++)
46  		continue;
47  
48  	if ((copy = malloc(len + 1)) == NULL)
49  		return (NULL);
50  	memcpy(copy, str, len);
51  	copy[len] = '\0';
52  	return (copy);
53  }