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https://github.com/jart/cosmopolitan.git
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6f7d0cb1c3
This makes breaking changes to add underscores to many non-standard function names provided by the c library. MODE=tiny is now tinier and we now use smaller locks that are better for tiny apps in this mode. Some headers have been renamed to be in the same folder as the build package, so it'll be easier to know which build dependency is needed. Certain old misguided interfaces have been removed. Intel intrinsics headers are now listed in libc/isystem (but not in the amalgamation) to help further improve open source compatibility. Header complexity has also been reduced. Lastly, more shell scripts are now available.
66 lines
3.2 KiB
C
66 lines
3.2 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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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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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/intrin/strace.internal.h"
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#include "libc/calls/syscall-nt.internal.h"
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#include "libc/calls/syscall-sysv.internal.h"
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#include "libc/dce.h"
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#include "libc/sysv/errfuns.h"
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/**
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* Duplicates file descriptor, granting it specific number.
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*
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* The `O_CLOEXEC` flag shall be cleared from the resulting file
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* descriptor; see dup3() to preserve it.
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*
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* Unlike dup3(), the dup2() function permits oldfd and newfd to be the
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* same, in which case the only thing this function does is test if
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* oldfd is open.
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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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* @raise EBADF is oldfd isn't open
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* @raise EBADF is newfd negative or too big
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* @raise EINTR if a signal handler was called
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* @asyncsignalsafe
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* @vforksafe
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*/
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int dup2(int oldfd, int newfd) {
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int rc;
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if (__isfdkind(oldfd, kFdZip)) {
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rc = eopnotsupp();
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} else if (!IsWindows()) {
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rc = sys_dup2(oldfd, newfd);
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} else if (newfd < 0) {
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rc = ebadf();
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} else if (oldfd == newfd) {
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if (__isfdopen(oldfd)) {
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rc = newfd;
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} else {
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rc = ebadf();
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}
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} else {
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rc = sys_dup_nt(oldfd, newfd, 0, -1);
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}
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STRACE("dup2(%d, %d) → %d% m", oldfd, newfd, rc);
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return rc;
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}
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