1 /* Invoke opendir, but avoid some glitches.
3 Copyright (C) 2009-2015 Free Software Foundation, Inc.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 /* Written by Eric Blake. */
22 #include "dirent-safer.h"
26 #include "unistd-safer.h"
28 /* Like opendir, but do not clobber stdin, stdout, or stderr. */
31 opendir_safer (char const *name
)
33 DIR *dp
= opendir (name
);
39 if (0 <= fd
&& fd
<= STDERR_FILENO
)
41 /* If fdopendir is native (as on Linux), then it is safe to
42 assume dirfd(fdopendir(n))==n. If we are using the
43 gnulib module fdopendir, then this guarantee is not met,
44 but fdopendir recursively calls opendir_safer up to 3
45 times to at least get a safe fd. If fdopendir is not
46 present but dirfd is accurate (as on cygwin 1.5.x), then
47 we recurse up to 3 times ourselves. Finally, if dirfd
48 always fails (as on mingw), then we are already safe. */
51 #if HAVE_FDOPENDIR || GNULIB_FDOPENDIR
52 int f
= dup_safer (fd
);
60 newdp
= fdopendir (f
);
65 #else /* !FDOPENDIR */
66 newdp
= opendir_safer (name
);