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 -*-│
|
|
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
|
│ Copyright 2020 Justine Alexandra Roberts Tunney │
|
|
│ │
|
|
│ Permission to use, copy, modify, and/or distribute this software for │
|
|
│ any purpose with or without fee is hereby granted, provided that the │
|
|
│ above copyright notice and this permission notice appear in all copies. │
|
|
│ │
|
|
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
|
|
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
|
|
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
|
|
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
|
|
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
|
|
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
|
|
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
|
|
│ PERFORMANCE OF THIS SOFTWARE. │
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
#include "libc/calls/calls.h"
|
|
#include "libc/calls/internal.h"
|
|
#include "libc/dce.h"
|
|
|
|
/**
|
|
* Duplicates file descriptor, granting it specific number.
|
|
*
|
|
* @param oldfd isn't closed afterwards
|
|
* @param newfd if already assigned, is silently closed beforehand;
|
|
* unless it's equal to oldfd, in which case dup2() is a no-op
|
|
* @return new file descriptor, or -1 w/ errno
|
|
* @asyncsignalsafe
|
|
* @syscall
|
|
*/
|
|
int dup2(int oldfd, int newfd) {
|
|
if (oldfd == newfd) return newfd;
|
|
if (!IsWindows()) {
|
|
return dup3$sysv(oldfd, newfd, 0);
|
|
} else {
|
|
return dup$nt(oldfd, newfd, 0);
|
|
}
|
|
}
|