/* Open a stream to a file.
   Copyright (C) 2007-2016 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.  */

/* If the user's config.h happens to include <stdio.h>, let it include only
   the system's <stdio.h> here, so that orig_freopen doesn't recurse to
   rpl_freopen.  */
#define __need_FILE
#include <config.h>

/* Get the original definition of freopen.  It might be defined as a macro.  */
#include <stdio.h>
#undef __need_FILE

#include <errno.h>

static FILE *
orig_freopen (const char *filename, const char *mode, FILE *stream)
{
  return freopen (filename, mode, stream);
}

/* Specification.  */
/* Write "stdio.h" here, not <stdio.h>, otherwise OSF/1 5.1 DTK cc eliminates
   this include because of the preliminary #include <stdio.h> above.  */
#include "stdio.h"

#include <string.h>

FILE *
rpl_freopen (const char *filename, const char *mode, FILE *stream)
{
  FILE *result;

#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
  if (filename != NULL && strcmp (filename, "/dev/null") == 0)
    filename = "NUL";
#endif

  /* Clear errno to check the success of freopen() with it */
  errno = 0;

  result = orig_freopen (filename, mode, stream);

#ifdef __KLIBC__
  /* On OS/2 kLIBC, freopen() returns NULL even if it is successful
     if filename is NULL. */
  if (!filename && !result && !errno)
    result = stream;
#endif

  return result;
}