public function text_or_binary()
	{
		if (substr($this->file->body, 0, 2) === "\xFE\xFF"
			|| substr($this->file->body, 0, 2) === "\xFF\xFE"
			|| substr($this->file->body, 0, 4) === "\x00\x00\xFE\xFF"
			|| substr($this->file->body, 0, 3) === "\xEF\xBB\xBF")
		{
			return 'text/plain';
		}
		elseif (preg_match('/[\x00-\x08\x0E-\x1A\x1C-\x1F]/', $this->file->body))
		{
			return 'application/octect-stream';
		}
		else
		{
			return 'text/plain';
		}
	}