Don't use nslookup at all. It's broken. If you must use shell commands, try dnsquery. To do it nicely in Perl, trying reading through Net::DNS. Otherwise I think you can use the gethostbyaddr family of functions.

I don't know what you mean by 'kill TTL' though. DNS queries have a TTL, like all other packets, and zone files have a set cache timeout (the 'DNS' TTL). But you can't alter that on someone elses DNS and you can clear the cache on your local DNS server by restarting it.

____________________
Jeremy
I didn't believe in evil until I dated it.