/* Copyright (C) 1993-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.

   As a special exception, if you link the code in this file with

   files compiled with a GNU compiler to produce an executable,

   that does not cause the resulting executable to be covered by

   the GNU Lesser General Public License.  This exception does not

   however invalidate any other reasons why the executable file

   might be covered by the GNU Lesser General Public License.

   This exception applies to code released by its copyright holders

   in files containing the exception.  */

/*

   Copyright (C) 1990 The Regents of the University of California.

   All rights reserved.

   Redistribution and use in source and binary forms, with or without

   modification, are permitted provided that the following conditions

   are met:

   1. Redistributions of source code must retain the above copyright

      notice, this list of conditions and the following disclaimer.

   2. Redistributions in binary form must reproduce the above copyright

      notice, this list of conditions and the following disclaimer in the

      documentation and/or other materials provided with the distribution.

   4. Neither the name of the University nor the names of its contributors

      may be used to endorse or promote products derived from this software

      without specific prior written permission.

   THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND

   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

   ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE

   FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

   OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

   OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

   SUCH DAMAGE.*/

/* Modified for GNU iostream by Per Bothner 1991, 1992. */

#include "libioP.h"

#include <device-nrs.h>

#include <sys/stat.h>

#include <stdlib.h>

#include <unistd.h>

/* Return the result of isatty, without changing errno.  */

static int

local_isatty (int fd)

{

  int save_errno = errno;

  int res = __isatty (fd);

  __set_errno (save_errno);

  return res;

}

/* Allocate a file buffer, or switch to unbuffered I/O.  Streams for

   TTY devices default to line buffered.  */

int

_IO_file_doallocate (FILE *fp)

{

  size_t size;

  char *p;

  struct stat64 st;

  size = BUFSIZ;

  if (fp->_fileno >= 0 && __builtin_expect (_IO_SYSSTAT (fp, &st), 0) >= 0)

    {

      if (S_ISCHR (st.st_mode))

	{

	  /* Possibly a tty.  */

	  if (

#ifdef DEV_TTY_P

	      DEV_TTY_P (&st) ||

#endif

	      local_isatty (fp->_fileno))

	    fp->_flags |= _IO_LINE_BUF;

	}

#if defined _STATBUF_ST_BLKSIZE

      if (st.st_blksize > 0 && st.st_blksize < BUFSIZ)

	size = st.st_blksize;

#endif

    }

  p = malloc (size);

  if (__glibc_unlikely (p == NULL))

    return EOF;

  _IO_setb (fp, p, p + size, 1);

  return 1;

}

libc_hidden_def (_IO_file_doallocate)