Running the client: ./client username [host] [port]
Takes a mandatory username (maximum 31 characters). The host and port are optional, and they default to localhost and port 2000.
Once connected, the client should receive a greeting from the server. The client can then send and receive messages.
To quit, either send EOF with control-D, or type "/q".
Running the server: ./server [port]
The port is optional and defaults to 2000.