I had the same problems when I tried something vaguely similar.

Reads are blocking, so if the input ends unexpectedly, you're stuck. Try using the select http://perldoc.perl.org/functions/select.html function to test whether there is any data to read, and nibble the input one character at a time. If your input terminates without a \n then you'll time out the select instead of reading blindly and getting stuck.