Laboratory for week 2

1. In your echo project from last week, the client just sends the
string 'Hello world'.  Modify your client to prompt for the string to
send.  Test on localhost to confirm that the client receives the same
string it sends.  Then run your modified echo client on your server.

2. Create a new project recho (repeat echo).  Write an recho
client/server pair where the client repeatedly prompts for a string,
sends it, the server echoes it, and the client receives and prints the
response, repeating the send/echo/receive/print cycle until the user
enters an empty string at the prompt (by just typing RETURN but
nothing else).  Test on localhost, then run on your server.  On the
server, use different port numbers for the echo server and the recho
server, and run both at once.