ack/lang/cem/libcc.ansi/stdio/ftell.c

/*
 * ftell.c - obtain the value of the file-position indicator of a stream
 */
/* $Id$ */

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

long ftell(FILE* stream)
{
	long result;
	int adjust = 0;

	if (io_testflag(stream, _IOREADING))
		adjust = -stream->_count;
	else if (io_testflag(stream, _IOWRITING)
	    && stream->_buf
	    && !io_testflag(stream, _IONBF))
		adjust = stream->_ptr - stream->_buf;
	else
		adjust = 0;

	result = lseek(fileno(stream), 0, SEEK_CUR);

	if (result == -1)
		return result;

	result += (long)adjust;
	return result;
}