I have this problem where I have a RPz(W) and now and then the
wlan0 interface goes down.
I don't know if it is because the WAP goes down - which I hope it isn't happening - or something on the RPI is stopping the interface for a while.
So, where I am at now is how to detect when
wlan0 goes down.
Sorry if this is a dumb question. I seem to be good at asking them.