/*
 * fflush.c - flush stream(s)
 */
/* $Id$ */

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include "loc_incl.h"

int fflush(FILE* stream)
{
	int count, c1, i, retval = 0;

	if (!stream)
	{
		for (i = 0; i < FOPEN_MAX; i++)
			if (__iotab[i] && fflush(__iotab[i]))
				retval = EOF;
		return retval;
	}

	if (!stream->_buf
	    || (!io_testflag(stream, _IOREADING)
	           && !io_testflag(stream, _IOWRITING)))
		return 0;
	if (io_testflag(stream, _IOREADING))
	{
		/* (void) fseek(stream, 0L, SEEK_CUR); */
		int adjust = 0;
		if (stream->_buf && !io_testflag(stream, _IONBF))
			adjust = stream->_count;
		stream->_count = 0;
		lseek(fileno(stream), (off_t)adjust, SEEK_CUR);
		if (io_testflag(stream, _IOWRITE))
			stream->_flags &= ~(_IOREADING | _IOWRITING);
		stream->_ptr = stream->_buf;
		return 0;
	}
	else if (io_testflag(stream, _IONBF))
		return 0;

	if (io_testflag(stream, _IOREAD)) /* "a" or "+" mode */
		stream->_flags &= ~_IOWRITING;

	count = stream->_ptr - stream->_buf;
	stream->_ptr = stream->_buf;

	if (count <= 0)
		return 0;

	if (io_testflag(stream, _IOAPPEND))
	{
		if (lseek(fileno(stream), 0L, SEEK_END) == -1)
		{
			stream->_flags |= _IOERR;
			return EOF;
		}
	}
	c1 = write(stream->_fd, (char*)stream->_buf, count);

	stream->_count = 0;

	if (count == c1)
		return 0;

	stream->_flags |= _IOERR;
	return EOF;
}

static void cleanup(void)
{
	register int i;

	for (i = 0; i < FOPEN_MAX; i++)
		if (__iotab[i] && io_testflag(__iotab[i], _IOWRITING))
			(void)fflush(__iotab[i]);
}

void __register_stdio_cleanup(void)
{
	static char registered = 0;
	if (!registered)
	{
		registered = 1;
		atexit(cleanup);
	}
}