mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-25 22:40:05 +00:00
71 lines
2.4 KiB
C
71 lines
2.4 KiB
C
/* Copyright (C) 1991, 1992, 1993, 1995 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 Library General Public License as
|
|
published by the Free Software Foundation; either version 2 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If
|
|
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
|
|
Cambridge, MA 02139, USA. */
|
|
|
|
#include <ansidecl.h>
|
|
#include <stdio.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <unistd.h>
|
|
|
|
/* Initialize STREAM as necessary.
|
|
This may change I/O functions, give a buffer, etc.
|
|
If no buffer is allocated, but the bufsize is set,
|
|
the bufsize will be used to allocate the buffer. */
|
|
void
|
|
DEFUN(__stdio_init_stream, (stream), FILE *stream)
|
|
{
|
|
register CONST int fd = (int) stream->__cookie;
|
|
struct stat statb;
|
|
|
|
if (stream->__buffer != NULL || stream->__userbuf)
|
|
/* If's unbuffered by request, we can't do anything useful. */
|
|
return;
|
|
|
|
/* Find out what sort of file this is. */
|
|
if (__fstat (fd, &statb) < 0)
|
|
return;
|
|
|
|
if (S_ISCHR (statb.st_mode))
|
|
{
|
|
/* It's a character device.
|
|
Make it line-buffered if it's a terminal. */
|
|
if (__isatty (fd))
|
|
{
|
|
stream->__linebuf = 1;
|
|
|
|
/* Unix terminal devices have the bad habit of claiming to be
|
|
seekable. On systems I have tried, seeking on a terminal
|
|
device seems to set its file position as specified, such that
|
|
a later tell says the same thing. This is in no way related
|
|
to actual seekability--the ability to seek back and read old
|
|
data. Unix terminal devices will let you "seek back", and
|
|
then read more new data from the terminal. I can think of
|
|
nothing to do about this lossage except to preemptively disable
|
|
seeking on terminal devices. */
|
|
|
|
stream->__io_funcs.__seek = NULL; /* Seeks get ESPIPE. */
|
|
}
|
|
}
|
|
|
|
#ifdef _STATBUF_ST_BLKSIZE
|
|
/* Use the block-size field to determine
|
|
the system's optimal buffering size. */
|
|
stream->__bufsize = statb.st_blksize;
|
|
#endif
|
|
}
|