Hi Chris.

This is not a stupid question. Consider using a couple of modules for the validation tasks, viz., Regexp::Common (for IP addresses) and Data::Validate::Domain.

Given these, you can do the following:

use strict;
use warnings;
use Regexp::Common qw/net/;
use Data::Validate::Domain qw(is_domain);

my $form = 'This is my form stuff.';

while ( my $input = <DATA> ) {
    chomp $input;
    my $results = ( $input =~ /$RE{net}{IPv4}/ or is_domain($input) ) 
+? $input : $form;
    print "Input: $input; Results: $results\n";
}

__DATA__
66.39.54.27

perlmonks.com
555.666.777.999
192.168.0.1
%^&.#@!.com

[download]

Output:

Input: 66.39.54.27; Results: 66.39.54.27
Input: ; Results: This is my form stuff.
Input: perlmonks.com; Results: perlmonks.com
Input: 555.666.777.999; Results: This is my form stuff.
Input: 192.168.0.1; Results: 192.168.0.1
Input: %^&.#@!.com; Results: This is my form stuff.

[download]

The validation results are generated using the ternary operator and the modules' offerings: $input is returned if it's a valid IP or domain; anything else returns $form.

Hope this helps!

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

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