[Maria-discuss] Easy way to see different users@hosts connected to all databases?

Is there a simple command I can issue to see a list of the current users@hosts connected to all of the databases of a running mariadb server? I'm trying to troubleshoot a problem where an update from 5.5.30 to 5.5.37 recently caused all of the connections from my groupware host to start coming from a different hostname, and so were being denied. I need to be able to see if changes that I make change the hostname being used. Thanks, Charles