From: "Tony Finch" <dot(_at_)dotat(_dot_)at>
helo 65.10.44.25
This would be an illegal syntax per the ABNF:
How do you know it's not a domain? Do you perform a DNS lookup?
See the discussion in RFC 1123 section 2.1: "a valid host name can never
have the dotted-decimal form #.#.#.#, since at least the highest-level
component label will be alphabetic."
Right, the TLD (the far right .#) can not be alphanumeric. (Probably it can
also be said it is known to not exist for registered top-level domains in
ICANN.)
I do a inet_addr() conversion and if this comes back as INADDR_NONE (-1),
then you know its not a valid dotted-decimal format.
--
Hector Santos, Santronics Software, Inc.
http://www.santronics.com