/*-*- 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/calls/syscall-nt.internal.h" #include "libc/calls/syscall-sysv.internal.h" #include "libc/dce.h" #include "libc/intrin/strace.internal.h" #include "libc/sysv/consts/o.h" #include "libc/sysv/errfuns.h" /** * Duplicates file descriptor/handle. * * On Windows, we can't guarantee the desired file descriptor is used. * We can however remap the standard handles (non-atomically) if their * symbolic names are used. * * @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 * @param flags may have O_CLOEXEC which is needed to preserve the * close-on-execve() state after file descriptor duplication * @return newfd on success, or -1 w/ errno * @raise ENOTSUP if `oldfd` is a zip file descriptor * @raise EPERM if pledge() is in play without stdio * @raise EINVAL if `flags` has unsupported bits * @raise EINTR if a signal handler was called * @raise EBADF is `newfd` negative or too big * @raise EINVAL if `newfd` equals oldfd * @raise EBADF is `oldfd` isn't open * @see dup(), dup2() */ int dup3(int oldfd, int newfd, int flags) { int rc; if (oldfd == newfd || (flags & ~O_CLOEXEC)) { rc = einval(); // NetBSD doesn't do this } else if (oldfd < 0 || newfd < 0) { rc = ebadf(); } else if (__isfdkind(oldfd, kFdZip)) { rc = enotsup(); } else if (!IsWindows()) { rc = sys_dup3(oldfd, newfd, flags); } else { rc = sys_dup_nt(oldfd, newfd, flags, -1); } STRACE("dup3(%d, %d, %d) → %d% m", oldfd, newfd, flags, rc); return rc; }