In a Linux environment, you can quickly check the status of a number of
different services. By running [sudo] service --status-all, the status
command will be invoked for all services under the /etc/init.d/ directory.
So, if you want to check the status of something like nginx or apache,
just run service --status-all and find it in the list. The - symbol
means it isn't running, the + symbol means it is up, and the ? symbol
means that it cannot determine the status.