1 /* Implement the strndup function.
2 Copyright (C) 2005-2020 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 strnlen (const char *s, size_t maxlen);
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 = strnlen (s, n);
45
46 result = (char *) malloc (len + 1);
47 if (!result)
48 return 0;
49
50 result[len] = '\0';
51 return (char *) memcpy (result, s, len);
52 }
53