Really, you searched google? What are you searching for exactly? A search for your 'unknown error' "No valid response for 4th time" points to the module Net::Whois::IP, which oddly enough, you are using. While it is important to learn how to use search engines properly, it is also important to read the code and documentation of the modules you are using.

I suggest you read the code of Net::Whois::IP, which suggests you are not getting a valid response from the registrar.

Also, use strict; and use warnings; and basic error checking seem to be missing from your code.

Update: typo s/strinct/strict/ thanks jettero, note to self, never attempt posting on no sleep and zero caffeine.

Update 2: print OUTPUT $lines[0]."-".$lines[1].\n"; should be print OUTPUT $lines[0]."-".$lines[1]."\n";

Hope this helps

Martin