/* Retrieve information about a FILE stream.
   Copyright (C) 2007 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 2, 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, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

#include <config.h>

/* Specification.  */
#include "fbufmode.h"

#if HAVE___FLBF
# include <stdio_ext.h>
#endif

int
fbufmode (FILE *fp)
{
  /* Most systems provide FILE as a struct and the necessary bitmask in
     <stdio.h>, because they need it for implementing getc() and putc() as
     fast macros.  */
#if defined _IO_ferror_unlocked     /* GNU libc, BeOS */
# if HAVE___FLBF                    /* glibc >= 2.2 */
  if (__flbf (fp))
    return _IOLBF;
# else
  if (fp->_flags & _IO_LINE_BUF)
    return _IOLBF;
# endif
  if (fp->_flags & _IO_UNBUFFERED)
    return _IONBF;
  return _IOFBF;
#elif defined __sferror             /* FreeBSD, NetBSD, OpenBSD, MacOS X, Cygwin */
  if (fp->_flags & __SLBF)
    return _IOLBF;
  if (fp->_flags & __SNBF)
    return _IONBF;
  return _IOFBF;
#elif defined _IOERR                /* AIX, HP-UX, IRIX, OSF/1, Solaris, mingw */
# if HAVE___FLBF                    /* Solaris >= 7 */
  if (__flbf (fp))
    return _IOLBF;
# else
  if (fp->_flag & _IOLBF)
    return _IOLBF;
# endif
  if (fp->_flag & _IONBF)
    return _IONBF;
  return _IOFBF;
#else
 #error "Please port gnulib fbufmode.c to your platform! Look at the setvbuf implementation."
#endif
}