1 /* Implement the strndup function.
2    Copyright (C) 2005 Free Software Foundation, Inc.
3    Written by Kaveh R. Ghazi <ghazi@caip.rutgers.edu>.
4 
5 This file is part of the libiberty library.
6 Libiberty is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public
8 License as published by the Free Software Foundation; either
9 version 2 of the License, or (at your option) any later version.
10 
11 Libiberty is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 Library General Public License for more details.
15 
16 You should have received a copy of the GNU Library General Public
17 License along with libiberty; see the file COPYING.LIB.  If
18 not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
19 Boston, MA 02110-1301, USA.  */
20 
21 /*
22 
23 @deftypefn Extension char* strndup (const char *@var{s}, size_t @var{n})
24 
25 Returns a pointer to a copy of @var{s} with at most @var{n} characters
26 in memory obtained from @code{malloc}, or @code{NULL} if insufficient
27 memory was available.  The result is always NUL terminated.
28 
29 @end deftypefn
30 
31 */
32 
33 #include "ansidecl.h"
34 #include <stddef.h>
35 
36 extern size_t	strlen (const char*);
37 extern PTR	malloc (size_t);
38 extern PTR	memcpy (PTR, const PTR, size_t);
39 
40 char *
strndup(const char * s,size_t n)41 strndup (const char *s, size_t n)
42 {
43   char *result;
44   size_t len = strlen (s);
45 
46   if (n < len)
47     len = n;
48 
49   result = (char *) malloc (len + 1);
50   if (!result)
51     return 0;
52 
53   result[len] = '\0';
54   return (char *) memcpy (result, s, len);
55 }
56