| /* Duplicate an open file descriptor to a specified file descriptor. |
| |
| Copyright (C) 1999, 2004-2007, 2009-2016 Free Software Foundation, Inc. |
| |
| This program is free software: you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| /* written by Paul Eggert */ |
| |
| #include <config.h> |
| |
| /* Specification. */ |
| #include <unistd.h> |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| |
| #if HAVE_DUP2 |
| |
| # undef dup2 |
| |
| # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ |
| |
| /* Get declarations of the native Windows API functions. */ |
| # define WIN32_LEAN_AND_MEAN |
| # include <windows.h> |
| |
| # include "msvc-inval.h" |
| |
| /* Get _get_osfhandle. */ |
| # include "msvc-nothrow.h" |
| |
| static int |
| ms_windows_dup2 (int fd, int desired_fd) |
| { |
| int result; |
| |
| /* If fd is closed, mingw hangs on dup2 (fd, fd). If fd is open, |
| dup2 (fd, fd) returns 0, but all further attempts to use fd in |
| future dup2 calls will hang. */ |
| if (fd == desired_fd) |
| { |
| if ((HANDLE) _get_osfhandle (fd) == INVALID_HANDLE_VALUE) |
| { |
| errno = EBADF; |
| return -1; |
| } |
| return fd; |
| } |
| |
| /* Wine 1.0.1 return 0 when desired_fd is negative but not -1: |
| http://bugs.winehq.org/show_bug.cgi?id=21289 */ |
| if (desired_fd < 0) |
| { |
| errno = EBADF; |
| return -1; |
| } |
| |
| TRY_MSVC_INVAL |
| { |
| result = dup2 (fd, desired_fd); |
| } |
| CATCH_MSVC_INVAL |
| { |
| errno = EBADF; |
| result = -1; |
| } |
| DONE_MSVC_INVAL; |
| |
| if (result == 0) |
| result = desired_fd; |
| |
| return result; |
| } |
| |
| # define dup2 ms_windows_dup2 |
| |
| # elif defined __KLIBC__ |
| |
| # include <InnoTekLIBC/backend.h> |
| |
| static int |
| klibc_dup2dirfd (int fd, int desired_fd) |
| { |
| int tempfd; |
| int dupfd; |
| |
| tempfd = open ("NUL", O_RDONLY); |
| if (tempfd == -1) |
| return -1; |
| |
| if (tempfd == desired_fd) |
| { |
| close (tempfd); |
| |
| char path[_MAX_PATH]; |
| if (__libc_Back_ioFHToPath (fd, path, sizeof (path))) |
| return -1; |
| |
| return open(path, O_RDONLY); |
| } |
| |
| dupfd = klibc_dup2dirfd (fd, desired_fd); |
| |
| close (tempfd); |
| |
| return dupfd; |
| } |
| |
| static int |
| klibc_dup2 (int fd, int desired_fd) |
| { |
| int dupfd; |
| struct stat sbuf; |
| |
| dupfd = dup2 (fd, desired_fd); |
| if (dupfd == -1 && errno == ENOTSUP \ |
| && !fstat (fd, &sbuf) && S_ISDIR (sbuf.st_mode)) |
| { |
| close (desired_fd); |
| |
| return klibc_dup2dirfd (fd, desired_fd); |
| } |
| |
| return dupfd; |
| } |
| |
| # define dup2 klibc_dup2 |
| # endif |
| |
| int |
| rpl_dup2 (int fd, int desired_fd) |
| { |
| int result; |
| |
| # ifdef F_GETFL |
| /* On Linux kernels 2.6.26-2.6.29, dup2 (fd, fd) returns -EBADF. |
| On Cygwin 1.5.x, dup2 (1, 1) returns 0. |
| On Cygwin 1.7.17, dup2 (1, -1) dumps core. |
| On Cygwin 1.7.25, dup2 (1, 256) can dump core. |
| On Haiku, dup2 (fd, fd) mistakenly clears FD_CLOEXEC. */ |
| # if HAVE_SETDTABLESIZE |
| setdtablesize (desired_fd + 1); |
| # endif |
| if (desired_fd < 0) |
| fd = desired_fd; |
| if (fd == desired_fd) |
| return fcntl (fd, F_GETFL) == -1 ? -1 : fd; |
| # endif |
| |
| result = dup2 (fd, desired_fd); |
| |
| /* Correct an errno value on FreeBSD 6.1 and Cygwin 1.5.x. */ |
| if (result == -1 && errno == EMFILE) |
| errno = EBADF; |
| # if REPLACE_FCHDIR |
| if (fd != desired_fd && result != -1) |
| result = _gl_register_dup (fd, result); |
| # endif |
| return result; |
| } |
| |
| #else /* !HAVE_DUP2 */ |
| |
| /* On older platforms, dup2 did not exist. */ |
| |
| # ifndef F_DUPFD |
| static int |
| dupfd (int fd, int desired_fd) |
| { |
| int duplicated_fd = dup (fd); |
| if (duplicated_fd < 0 || duplicated_fd == desired_fd) |
| return duplicated_fd; |
| else |
| { |
| int r = dupfd (fd, desired_fd); |
| int e = errno; |
| close (duplicated_fd); |
| errno = e; |
| return r; |
| } |
| } |
| # endif |
| |
| int |
| dup2 (int fd, int desired_fd) |
| { |
| int result = fcntl (fd, F_GETFL) < 0 ? -1 : fd; |
| if (result == -1 || fd == desired_fd) |
| return result; |
| close (desired_fd); |
| # ifdef F_DUPFD |
| result = fcntl (fd, F_DUPFD, desired_fd); |
| # if REPLACE_FCHDIR |
| if (0 <= result) |
| result = _gl_register_dup (fd, result); |
| # endif |
| # else |
| result = dupfd (fd, desired_fd); |
| # endif |
| if (result == -1 && (errno == EMFILE || errno == EINVAL)) |
| errno = EBADF; |
| return result; |
| } |
| #endif /* !HAVE_DUP2 */ |