1 /* Copyright (C) 1991-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <errno.h>
19 #include <fcntl.h>
20 #include <unistd.h>
21
22
23 /* Duplicate FD to FD2, closing the old FD2 and making FD2 be
24 open the same file as FD is. Return FD2 or -1. */
25 int
__dup2(int fd,int fd2)26 __dup2 (int fd, int fd2)
27 {
28 if (fd < 0 || fd2 < 0)
29 {
30 __set_errno (EBADF);
31 return -1;
32 }
33
34 if (fd == fd2)
35 /* No way to check that they are valid. */
36 return fd2;
37
38 __set_errno (ENOSYS);
39 return -1;
40 }
41 libc_hidden_def (__dup2)
42 stub_warning (dup2)
43
44 weak_alias (__dup2, dup2)
45