Write a very short application which relies mostly on a module you have in your Perl tree, which lives outside of the webroot. It limits the interference with your scripts if there is any breach in security on the webserver. They can then read your application and change it, but the main part of the code would be beyond them (well, nothing ever is 100% safe, but that is no reason not to aim for the best possible solution).
CountZero
"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law