#!/usr/bin/perl --
use strict; use warnings;
use Iterator::Files;

my $search = quotemeta `uname -r`;
my $input = Iterator::Files->new( files => [ '/etc/hosts' ], );

while( <$input> ){
    s/$uname/$answer1/g;
    s/\Qdomainsuffix.net\E/$answer4/g;
}