| 1 | /* Copyright (C) 2011-2022 Free Software Foundation, Inc. |
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| 2 | This file is part of the GNU C Library. |
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| 3 | |
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| 4 | The GNU C Library is free software; you can redistribute it and/or |
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| 5 | modify it under the terms of the GNU Lesser General Public |
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| 6 | License as published by the Free Software Foundation; either |
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| 7 | version 2.1 of the License, or (at your option) any later version. |
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| 8 | |
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| 9 | The GNU C Library is distributed in the hope that it will be useful, |
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| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 12 | Lesser General Public License for more details. |
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| 13 | |
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| 14 | You should have received a copy of the GNU Lesser General Public |
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| 15 | License along with the GNU C Library. If not, see |
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| 16 | <https://www.gnu.org/licenses/>. */ |
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| 17 | |
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| 18 | #include <fcntl.h> |
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| 19 | #include <unistd.h> |
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| 20 | #include <sysdep.h> |
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| 21 | |
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| 22 | /* Duplicate FD to FD2, closing the old FD2 and making FD2 be |
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| 23 | open the same file as FD is. Return FD2 or -1. */ |
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| 24 | int |
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| 25 | __dup2 (int fd, int fd2) |
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| 26 | { |
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| 27 | /* For the degenerate case, check if the fd is valid (by trying to |
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| 28 | get the file status flags) and return it, or else return EBADF. */ |
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| 29 | if (fd == fd2) |
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| 30 | return __libc_fcntl (fd, F_GETFL, 0) < 0 ? -1 : fd; |
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| 31 | |
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| 32 | return INLINE_SYSCALL (dup3, 3, fd, fd2, 0); |
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| 33 | } |
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| 34 | libc_hidden_def (__dup2) |
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| 35 | weak_alias (__dup2, dup2) |
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| 36 | |
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