1 /* provide a replacement fdopendir function
2 Copyright (C) 2004-2010 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17 /* written by Jim Meyering */
29 # include "openat-priv.h"
30 # include "save-cwd.h"
32 # if GNULIB_DIRENT_SAFER
33 # include "dirent--.h"
36 /* Replacement for Solaris' function by the same name.
37 <http://www.google.com/search?q=fdopendir+site:docs.sun.com>
38 First, try to simulate it via opendir ("/proc/self/fd/FD"). Failing
39 that, simulate it by using fchdir metadata, or by doing
40 save_cwd/fchdir/opendir(".")/restore_cwd.
41 If either the save_cwd or the restore_cwd fails (relatively unlikely),
42 then give a diagnostic and exit nonzero.
43 Otherwise, this function works just like Solaris' fdopendir.
46 Unlike other fd-related functions, this one effectively consumes
47 its FD parameter. The caller should not close or otherwise
48 manipulate FD if this function returns successfully. Also, this
49 implementation does not guarantee that dirfd(fdopendir(n))==n;
50 the open directory stream may use a clone of FD, or have no
51 associated fd at all. */
58 char buf[OPENAT_BUFFER_SIZE];
59 char *proc_file = openat_proc_name (buf, fd, ".");
62 dir = opendir (proc_file);
68 saved_errno = EOPNOTSUPP;
71 /* If the syscall fails with an expected errno value, resort to
72 save_cwd/restore_cwd. */
73 if (! dir && EXPECTED_ERRNO (saved_errno))
76 const char *name = _gl_directory_name (fd);
80 # else /* !REPLACE_FCHDIR */
81 struct saved_cwd saved_cwd;
82 if (save_cwd (&saved_cwd) != 0)
83 openat_save_fail (errno);
95 if (restore_cwd (&saved_cwd) != 0)
96 openat_restore_fail (errno);
99 free_cwd (&saved_cwd);
100 # endif /* !REPLACE_FCHDIR */
105 if (proc_file != buf)
111 #else /* HAVE_FDOPENDIR */
114 # include <sys/stat.h>
118 /* Like fdopendir, but work around GNU/Hurd bug by validating FD. */
121 rpl_fdopendir (int fd)
126 if (!S_ISDIR (st.st_mode))
131 return fdopendir (fd);
134 #endif /* HAVE_FDOPENDIR */