Mit der Shell kann man unter Linux sehr schöne Sachen machen 
Daher hier verschiedene Shell (meist Bash) Scripte
TypeError: array_keys(): Argument #1 ($array) must be of type array, null given
An unforeseen error has occured. This is most likely a bug somewhere. It might be a problem in the discussion plugin.
More info has been written to the DokuWiki error log.