in reply to
getting list of IP's from range
your idea of splitting and using the range operator is quite faster and perl-ish way of doing.
however can you pass that many IPs(after elaborating the range) to the client script, will it handle that many arguments properly?.
-- In accordance with the prarabdha of each, the One whose function it is to ordain makes each to act. What will not happen will never happen, whatever effort one may put forth. And what will happen will not fail to happen, however much one may seek to prevent it. This is certain. The part of wisdom therefore is to stay quiet.