glibc/libio/filedoalloc.c

133 lines
4.5 KiB
C

/* 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 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)