The getlines() work just like it does on files. When the socket has finished an EOF is sent, just like when working with files.

IO::Socket has a parameter called Listen. This controls the number of connections that can be waiting for an accept. I.E. if you have Listen => 10, if 11 people connect to your server while it is busy, 10 people will be waiting, and 1 person will get a server busy error.

I hope this answers your questions.