-p configures non-standard ports, and is one of: -p <start port num> custom cases -p rand for shared systems, use a random start port number between 9000 and 49000 that is divisible by 200 -p fromDisplay if you are running on a VNC session
-y answers interactive questions implicitly with yes
-n takes no action, useful with -v
-v lists the port values used
See script header for use of optional environment variables.