text: /* Copyright (C) 1993, 1997, 2001-2002, 2011-2012 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. */
  
  #ifndef _POSIX_SOURCE
  # define _POSIX_SOURCE
  #endif
  #include "libioP.h"
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <stdlib.h>
  #include <unistd.h>
  
  #ifdef _LIBC
  # undef isatty
  # define isatty(Fd) __isatty (Fd)
  
  # include <device-nrs.h>
  #endif
  
  
  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.
   * Per the ANSI C standard, ALL tty devices default to line buffered.
   *
   * As a side effect, we set __SOPT or __SNPT (en/dis-able fseek
   * optimisation) right after the _fstat() that finds the buffer size.
   */
  
  int
  _IO_file_doallocate (fp)
       _IO_FILE *fp;
  {
    _IO_size_t size;
    char *p;
    struct _G_stat64 st;
  
  #ifndef _LIBC
    /* If _IO_cleanup_registration_needed is non-zero, we should call the
       function it points to.  This is to make sure _IO_cleanup gets called
       on exit.  We call it from _IO_file_doallocate, since that is likely
       to get called by any program that does buffered I/O. */
    if (__builtin_expect (_IO_cleanup_registration_needed != NULL, 0))
      (*_IO_cleanup_registration_needed) ();
  #endif
  
    size = _IO_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 _IO_HAVE_ST_BLKSIZE
        if (st.st_blksize > 0)
  	size = st.st_blksize;
  #endif
      }
    ALLOC_BUF (p, size, EOF);
    _IO_setb (fp, p, p + size, 1);
    return 1;
  }
  libc_hidden_def (_IO_file_doallocate)
  