use strict;
use warnings;

# Using block lexical scope to data-hide %junksites
{
    my %junksites = (
        'bollyinside.com' => 1,
        'www.bollyinside.com' => 1,
        'worldtrademarkreview.com' => 1,
        'www.worldtrademarkreview.com' => 1,
    );

    sub KnownJunkSite {
        my $val = shift;
        return exists $junksites{$val};
    }
}

for my $v ('bollyinside.com', 'fred', 'www.worldtrademarkreview.com') {
    print "$v: ", KnownJunkSite($v) ? "found\n" : "not found\n";
}