该系统由一个知识库和三个子程序组成。

The system consists of a knowledge base and three subprograms.

设置了子程序后，我们将快速转入简短的主程序逻辑。

With our subroutines set up, we move quickly into the short main program logic.

利用这些子程序，主程序的逻辑允许用户创建敲打序列，或在守护模式下监听敲打序列并执行命令。

With the subroutines in place, the main program logic allows the user to create a knock sequence, or runs in daemon mode to listen for knocks and execute commands.