German Thermify: https://www.cloudandheat.com/

learn restic, too ;)

In Europe we have Buchschränke (Tauschschränke)

There’s a open street map tag: https://wiki.openstreetmap.org/wiki/Tag:amenity%3Dpublic_bookcase

In which f*ssil country is power cheaper at night!?

Explanation

[ is an alias for the program test, so you can call man test for more info.
&& is bash syntax for conjunction. In A && B, B will only be called if A returned a exit code >0 (error). You can call man bash for more info.
|| is bash syntax for disjunction. In A || B, B will only be called if A returned exit code =0 (success). true and false are programs that just return exit codes 0 respectively 1.