ReadMode 3;
    while ($input_thread_running > 0 && !$ret)
    {
        until (defined($key = ReadKey(0))) 	# wait for input
        {
            resize_input_window($input_window) if ($sizechanged);
        }

        if ($key == ERR)
        {
            threads->yield;
        }
        elsif ($key eq KEY_RESIZE)
        {
            set_resize_flag();
            threads->yield;
        }
        elsif (($key eq "\n") or ($key eq "\r"))			# return/newline
        {
            ...