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