I own a Synology diskstation which has the “surveillance station” on board which records content from any LAN (or WiFi)-enabled webcam and sends an alarm when someone is moving at my home. It is possible to enter time schedules when the camera should be enabled and when it shouldn’t. But that does not really work the way I wanted. When I come home earlier or even have a day off I have to disable the camera manually.
So I decided that I want to use my smartphone to trigger the surveillance mode. Like most of us I always carry the phone with me. So it should be easy: If the phone is at home, I am, too. So the camera should be off. The same way when I am not at home.
The solution for this was surprisingly simple: A small bash-script first checks if the phone is in the network. The Surveillance station cam gets enabled or disabled according to this one condition.