public function getFileData($file = null, $offset = null){
    	if(null === $file)$file = &$this->file;
    	if(null === $offset)$offset = $this->file_offset;
		$this->IO = fopen($file, 'r');
        fseek($this->IO, $offset);
        try{
			$this->raw =  stream_get_contents($this->IO);
		}catch(\Exception $e){
			$this->raw = '';
			trigger_error($e->getMessage(),  $this->e_level);
		}
        
        return $this->raw;
	}