1 | /* Copyright (C) 2011-2022 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 <fcntl.h> |
19 | #include <unistd.h> |
20 | #include <sysdep.h> |
21 | |
22 | /* Duplicate FD to FD2, closing the old FD2 and making FD2 be |
23 | open the same file as FD is. Return FD2 or -1. */ |
24 | int |
25 | __dup2 (int fd, int fd2) |
26 | { |
27 | /* For the degenerate case, check if the fd is valid (by trying to |
28 | get the file status flags) and return it, or else return EBADF. */ |
29 | if (fd == fd2) |
30 | return __libc_fcntl (fd, F_GETFL, 0) < 0 ? -1 : fd; |
31 | |
32 | return INLINE_SYSCALL (dup3, 3, fd, fd2, 0); |
33 | } |
34 | libc_hidden_def (__dup2) |
35 | weak_alias (__dup2, dup2) |
36 | |