/* Test of opening a file stream.

   Copyright (C) 2007-2017 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 Bruno Haible <bruno@clisp.org>, 2007.  */

#include <config.h>

#include <stdio.h>

#include "signature.h"

SIGNATURE_CHECK (freopen, FILE *, (char const *, char const *, FILE *));

#include <errno.h>

#include <unistd.h>

#include "macros.h"

int

main ()

{

  const char *filename = "test-freopen.txt";

  close (STDIN_FILENO);

  ASSERT (freopen ("/dev/null", "r", stdin) != NULL);

  ASSERT (getchar () == EOF);

  ASSERT (!ferror (stdin));

  ASSERT (feof (stdin));

#if 0 /* freopen (NULL, ...) is unsupported on most platforms.  */

  /* Test that freopen() sets errno if someone else closes the stream

     fd behind the back of stdio.  */

  {

    FILE *fp = fopen (filename, "w+");

    ASSERT (fp != NULL);

    ASSERT (close (fileno (fp)) == 0);

    errno = 0;

    ASSERT (freopen (NULL, "r", fp) == NULL);

    perror("freopen");

    ASSERT (errno == EBADF);

    fclose (fp);

  }

  /* Test that freopen() sets errno if the stream was constructed with

     an invalid file descriptor.  */

  {

    FILE *fp = fdopen (-1, "w+");

    if (fp != NULL)

      {

        errno = 0;

        ASSERT (freopen (NULL, "r", fp) == NULL);

        ASSERT (errno == EBADF);

        fclose (fp);

      }

  }

  {

    FILE *fp;

    close (99);

    fp = fdopen (99, "w+");

    if (fp != NULL)

      {

        errno = 0;

        ASSERT (freopen (NULL, "r", fp) == NULL);

        ASSERT (errno == EBADF);

        fclose (fp);

      }

  }

#endif

  /* Clean up.  */

  unlink (filename);

  return 0;

}