| /* Open a directory relative to another directory. |
| |
| Copyright 2006-2020 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 <https://www.gnu.org/licenses/>. |
| |
| Written by Jim Meyering and Paul Eggert. */ |
| |
| #include <config.h> |
| |
| #include <opendirat.h> |
| |
| #include <errno.h> |
| #include <fcntl--.h> |
| #include <unistd.h> |
| |
| /* Relative to DIR_FD, open the directory DIR, passing EXTRA_FLAGS to |
| the underlying openat call. On success, store into *PNEW_FD the |
| underlying file descriptor of the newly opened directory and return |
| the directory stream. On failure, return NULL and set errno. |
| |
| On success, *PNEW_FD is at least 3, so this is a "safer" function. */ |
| |
| DIR * |
| opendirat (int dir_fd, char const *dir, int extra_flags, int *pnew_fd) |
| { |
| int open_flags = (O_RDONLY | O_CLOEXEC | O_DIRECTORY | O_NOCTTY |
| | O_NONBLOCK | extra_flags); |
| int new_fd = openat (dir_fd, dir, open_flags); |
| |
| if (new_fd < 0) |
| return NULL; |
| DIR *dirp = fdopendir (new_fd); |
| if (dirp) |
| *pnew_fd = new_fd; |
| else |
| { |
| int fdopendir_errno = errno; |
| close (new_fd); |
| errno = fdopendir_errno; |
| } |
| return dirp; |
| } |