FWIW for other onlookers that this thread might attract...
It should be noted that, in order filter out only valid IP addresses;
one needs to modify the RE above: 
# FROM
my $results = ( $input =~ /$RE{net}{IPv4}/ or is_domain($input) ) ? $i
+nput : $form;

# TO
my $results = ( $input =~ /^$RE{net}{IPv4}$/ or is_domain($input) ) ? 
+$input : $form;

[download]
Take note of the additional anchor(s) in the second line.
Difference being; in the first line, the filter is an RE for any-and-all-digits && only-digits-3-or-less-in-length. While the second filters for: <=3-in-length && <=255-in-size.

HTH

--Chris

#!/usr/bin/perl -Tw
use perl::always;
my $perl_version = "5.12.5";
print $perl_version;

In reply to Re^5: How to best filter/direct data based on input structure? by taint
in thread How to best filter/direct data based on input structure? by taint

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