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/* Copyright (C) 1993, 1996, 1997, 1998 Free Software Foundation, Inc.
This file is part of the GNU IO Library.
This library 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 library 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 library; see the file COPYING. If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA.
As a special exception, if you link this library with files
compiled with a GNU compiler to produce an executable, this does
not cause the resulting executable to be covered by the GNU General
Public License. This exception does not however invalidate any
other reasons why the executable file might be covered by the GNU
General Public License. */
#include "libioP.h"
#define _IOFBF 0 /* Fully buffered. */
#define _IOLBF 1 /* Line buffered. */
#define _IONBF 2 /* No buffering. */
int
_IO_setvbuf (fp, buf, mode, size)
_IO_FILE *fp;
char *buf;
int mode;
_IO_size_t size;
{
int result;
CHECK_FILE (fp, EOF);
_IO_cleanup_region_start ((void (*) __P ((void *))) _IO_funlockfile, fp);
_IO_flockfile (fp);
switch (mode)
{
case _IOFBF:
fp->_IO_file_flags &= ~_IO_LINE_BUF|_IO_UNBUFFERED;
if (buf == NULL)
{
if (fp->_IO_buf_base == NULL)
{
/* There is no flag to distinguish between "fully buffered
mode has been explicitly set" as opposed to "line
buffering has not been explicitly set". In both
cases, _IO_LINE_BUF is off. If this is a tty, and
_IO_filedoalloc later gets called, it cannot know if
it should set the _IO_LINE_BUF flag (because that is
the default), or not (because we have explicitly asked
for fully buffered mode). So we make sure a buffer
gets allocated now, and explicitly turn off line
buffering.
A possibly cleaner alternative would be to add an
extra flag, but then flags are a finite resource. */
if (_IO_DOALLOCATE (fp) < 0)
{
result = EOF;
goto unlock_return;
}
fp->_IO_file_flags &= ~_IO_LINE_BUF;
}
result = 0;
goto unlock_return;
}
break;
case _IOLBF:
fp->_IO_file_flags &= ~_IO_UNBUFFERED;
fp->_IO_file_flags |= _IO_LINE_BUF;
if (buf == NULL)
{
result = 0;
goto unlock_return;
}
break;
case _IONBF:
buf = NULL;
size = 0;
break;
default:
result = EOF;
goto unlock_return;
}
result = _IO_SETBUF (fp, buf, size) == NULL ? EOF : 0;
unlock_return:
_IO_funlockfile (fp);
_IO_cleanup_region_end (0);
return result;
}
#ifdef weak_alias
weak_alias (_IO_setvbuf, setvbuf)
#endif
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