tests/test-fdopendir.c

   1 /* Test opening a directory stream from a file descriptor.
   2    Copyright (C) 2009-2021 Free Software Foundation, Inc.
   3
   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.
   8
   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.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Eric Blake <ebb9@byu.net>, 2009.  */
  18
  19 #include <config.h>
  20
  21 #include <dirent.h>
  22
  23 #include "signature.h"
  24 SIGNATURE_CHECK (fdopendir, DIR *, (int));
  25
  26 #include <errno.h>
  27 #include <fcntl.h>
  28 #include <unistd.h>
  29
  30 #include "macros.h"
  31
  32 int
  33 main (int argc _GL_UNUSED, char *argv[])
  34 {
  35   DIR *d;
  36   int fd;
  37
  38   /* A non-directory cannot be turned into a directory stream.  */
  39   fd = open ("test-fdopendir.tmp", O_RDONLY | O_CREAT, 0600);
  40   ASSERT (0 <= fd);
  41   errno = 0;
  42   ASSERT (fdopendir (fd) == NULL);
  43   ASSERT (errno == ENOTDIR);
  44   ASSERT (close (fd) == 0);
  45   ASSERT (unlink ("test-fdopendir.tmp") == 0);
  46
  47   /* A bad fd cannot be turned into a stream.  */
  48   {
  49     errno = 0;
  50     ASSERT (fdopendir (-1) == NULL);
  51     ASSERT (errno == EBADF);
  52   }
  53   {
  54     close (99);
  55     errno = 0;
  56     ASSERT (fdopendir (99) == NULL);
  57     ASSERT (errno == EBADF);
  58   }
  59
  60   /* This should work.  */
  61   fd = open (".", O_RDONLY);
  62   ASSERT (0 <= fd);
  63   d = fdopendir (fd);
  64   ASSERT (d);
  65   /* fdopendir should not close fd.  */
  66   ASSERT (dup2 (fd, fd) == fd);
  67
  68   /* Don't test dirfd here.  dirfd (d) must return fd on current POSIX
  69      platforms, but on pre-2008 platforms or on non-POSIX platforms
  70      dirfd (fd) might return some other descriptor, or -1, and gnulib
  71      does not work around this porting problem.  */
  72
  73   ASSERT (closedir (d) == 0);
  74   /* Now we can guarantee that fd must be closed.  */
  75   errno = 0;
  76   ASSERT (dup2 (fd, fd) == -1);
  77   ASSERT (errno == EBADF);
  78
  79   return 0;
  80 }