in reply to expect.pm header
$system, used in your header way at the top is never defined at all, let alone before it is used.
You need to re-evaluate how you are doing things. It looks like you want to create a header down after you define @systems, then iterate over that through each one and use something like"---$system[N]---\n".
...might have been useful, but I didn't test. Always use it.