Opsys Fall 2005
Sample Client and Server

This is a sample TCP based client and server.
The server provides a user name lookup service. Given a username
(login name) or userid, the server will look up the user's full
name and send it back to the client.

The file PROTOCOL describes the application protocol, here is a few
sample exchanges

client sends "username hollingd\n"
server responds with "OK Dave Hollinger\n"

client sends "userid 2575\n"
server responds with "OK Dave Hollinger\n"

client sends "userid 123456\n"
server responds with "ERR No such user\n"

client sends "Hello Server\n"
server responds with "ERR unknown command\n"