Check server deamon is running

I try to implement livestream functionality. My app works for show the livestream. (I use Raspian and mjpg-streamer to strem the video to a website and in the app).
Now I need to check if the "server deamon ‘mjpg-streamer’ runs actually. If not, show message and try to get content again. if deamon is running, do nothing.

How ist it possible to do that? I and google haven’t idea.


How are you displaying the livestream in your app?
What happens in your app when this daemon is not running?