129 lines
3.2 KiB
C
129 lines
3.2 KiB
C
/* Duplicate an open file descriptor to a specified file descriptor.
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Copyright (C) 1999, 2004-2007, 2009-2010 Free Software Foundation, Inc.
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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; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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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, see <http://www.gnu.org/licenses/>. */
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/* written by Paul Eggert */
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#include <config.h>
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/* Specification. */
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#include <unistd.h>
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#include <errno.h>
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#include <fcntl.h>
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#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
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/* Get declarations of the Win32 API functions. */
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# define WIN32_LEAN_AND_MEAN
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# include <windows.h>
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#endif
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#if HAVE_DUP2
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# undef dup2
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int
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rpl_dup2 (int fd, int desired_fd)
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{
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int result;
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# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
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/* If fd is closed, mingw hangs on dup2 (fd, fd). If fd is open,
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dup2 (fd, fd) returns 0, but all further attempts to use fd in
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future dup2 calls will hang. */
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if (fd == desired_fd)
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{
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if ((HANDLE) _get_osfhandle (fd) == INVALID_HANDLE_VALUE)
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{
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errno = EBADF;
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return -1;
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}
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return fd;
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}
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/* Wine 1.0.1 return 0 when desired_fd is negative but not -1:
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http://bugs.winehq.org/show_bug.cgi?id=21289 */
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if (desired_fd < 0)
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{
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errno = EBADF;
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return -1;
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}
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# endif
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result = dup2 (fd, desired_fd);
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# ifdef __linux__
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/* Correct a Linux return value.
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<http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.30.y.git;a=commitdiff;h=2b79bc4f7ebbd5af3c8b867968f9f15602d5f802>
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*/
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if (fd == desired_fd && result == (unsigned int) -EBADF)
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{
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errno = EBADF;
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result = -1;
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}
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# endif
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if (result == 0)
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result = desired_fd;
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/* Correct a cygwin 1.5.x errno value. */
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else if (result == -1 && errno == EMFILE)
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errno = EBADF;
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# if REPLACE_FCHDIR
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if (fd != desired_fd && result != -1)
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result = _gl_register_dup (fd, result);
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# endif
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return result;
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}
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#else /* !HAVE_DUP2 */
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/* On older platforms, dup2 did not exist. */
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# ifndef F_DUPFD
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static int
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dupfd (int fd, int desired_fd)
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{
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int duplicated_fd = dup (fd);
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if (duplicated_fd < 0 || duplicated_fd == desired_fd)
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return duplicated_fd;
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else
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{
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int r = dupfd (fd, desired_fd);
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int e = errno;
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close (duplicated_fd);
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errno = e;
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return r;
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}
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}
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# endif
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int
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dup2 (int fd, int desired_fd)
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{
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int result = fcntl (fd, F_GETFL) < 0 ? -1 : fd;
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if (result == -1 || fd == desired_fd)
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return result;
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close (desired_fd);
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# ifdef F_DUPFD
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result = fcntl (fd, F_DUPFD, desired_fd);
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# if REPLACE_FCHDIR
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if (0 <= result)
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result = _gl_register_dup (fd, result);
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# endif
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# else
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result = dupfd (fd, desired_fd);
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# endif
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if (result == -1 && (errno == EMFILE || errno == EINVAL))
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errno = EBADF;
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return result;
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}
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#endif /* !HAVE_DUP2 */
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