Something

	($disk_used, $disk_total) = split(/ /,$disk_long);
	@measurements = ['MB', 'GB', 'TB', 'YB'];
	while($disk_used >= 1024)
	{
		$disk_used_counter++;
		$disk_used /= 1024;
		$disk_used = sprintf("%.2f",$disk_used);
	}
	while($disk_total >= 1024)
	{
		$disk_total_counter++;
		$disk_total /= 1024;
		$disk_total = sprintf("%.2f",$disk_total);
	}
	$disk = " [Disk] " . $disk_used . $measurements[$disk_used_counter];