How to give some notification when code finish running?

While some code take a long time to finish, I usually do something else when running them.
It will be helpful to notify with a sound or system notification when finished.

我觉着吧，可以加个选项，ExecAfterFinished，这样执行完了，就可以调用 sox 播放提示音，或调用 notify-send 发通知了。
或者把运行状态输出到系统某个地方，这样可以写程序去监测。