41 lines
2.4 KiB
C
41 lines
2.4 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ This program is free software; you can redistribute it and/or modify │
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│ it under the terms of the GNU General Public License as published by │
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│ the Free Software Foundation; version 2 of the License. │
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│ │
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│ This program is distributed in the hope that it will be useful, but │
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│ WITHOUT ANY WARRANTY; without even the implied warranty of │
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│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
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│ General Public License for more details. │
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│ │
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│ You should have received a copy of the GNU General Public License │
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│ along with this program; if not, write to the Free Software │
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│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
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│ 02110-1301 USA │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/calls/calls.h"
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#include "libc/calls/internal.h"
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#include "libc/dce.h"
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/**
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* Duplicates file descriptor, granting it specific number.
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*
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* @param oldfd isn't closed afterwards
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* @param newfd if already assigned, is silently closed beforehand;
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* unless it's equal to oldfd, in which case dup2() is a no-op
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* @return new file descriptor, or -1 w/ errno
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* @asyncsignalsafe
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*/
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int dup2(int oldfd, int newfd) {
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if (oldfd == newfd) return newfd;
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if (!IsWindows()) {
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return dup3$sysv(oldfd, newfd, 0);
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} else {
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return dup$nt(oldfd, newfd, 0);
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}
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}
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