Here's what I suggest that you do.
use strict;
use warnings;
use Clue::ByFour;
use Existing::Client;
my $clueX4 = new Clue::ByFour;
my $client = new Existing::Client;
$clueX4->add("rusty nail");
$clueX4->target($client);
for (0..1000) {
$clueX4->swing();
}
Seriously. You need to at least make an attempt to enlighten the client about the Right Way (TM) to do this. You may THINK you have control over the format of the file, but some day down the line (sooner rather than later) and you or whoever works on this after you is in for a world of hurt. Security people are NOTORIOUSLY stupid about this sort of thing...they have policies that they have sat around and dreamed up and never even really considered the intelligence of.
You should have enough pride in your work to be SERIOUSLY po-ed about being asked to write shoddy 2nd rate code because of PHB's in the first place.
