/* Test opening a directory stream from a file descriptor.

   Copyright (C) 2009-2017 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 <http://www.gnu.org/licenses/>.  */

/* Written by Eric Blake <ebb9@byu.net>, 2009.  */

#include <config.h>

#include <dirent.h>

#include "signature.h"

SIGNATURE_CHECK (fdopendir, DIR *, (int));

#include <errno.h>

#include <fcntl.h>

#include <unistd.h>

#include "macros.h"

int

main (int argc _GL_UNUSED, char *argv[])

{

  DIR *d;

  int fd;

  /* A non-directory cannot be turned into a directory stream.  */

  fd = open ("test-fdopendir.tmp", O_RDONLY | O_CREAT, 0600);

  ASSERT (0 <= fd);

  errno = 0;

  ASSERT (fdopendir (fd) == NULL);

  ASSERT (errno == ENOTDIR);

  ASSERT (close (fd) == 0);

  ASSERT (unlink ("test-fdopendir.tmp") == 0);

  /* A bad fd cannot be turned into a stream.  */

  {

    errno = 0;

    ASSERT (fdopendir (-1) == NULL);

    ASSERT (errno == EBADF);

  }

  {

    close (99);

    errno = 0;

    ASSERT (fdopendir (99) == NULL);

    ASSERT (errno == EBADF);

  }

  /* This should work.  */

  fd = open (".", O_RDONLY);

  ASSERT (0 <= fd);

  d = fdopendir (fd);

  ASSERT (d);

  /* fdopendir should not close fd.  */

  ASSERT (dup2 (fd, fd) == fd);

  /* Don't test dirfd here.  dirfd (d) must return fd on current POSIX

     platforms, but on pre-2008 platforms or on non-POSIX platforms

     dirfd (fd) might return some other descriptor, or -1, and gnulib

     does not work around this porting problem.  */

  ASSERT (closedir (d) == 0);

  /* Now we can guarantee that fd must be closed.  */

  errno = 0;

  ASSERT (dup2 (fd, fd) == -1);

  ASSERT (errno == EBADF);

  return 0;

}