Unfortunately, Perl somewhat goes back to the philosophy held by an early (and probably apocryphal) COBOL compiler which, when given a copy of Lincoln's Gettysburg Address as input, “compiled it.”

The philosophy of “there's more than one way to do it” presupposes that the writer knew what he was doing and that your (the computer's) interpretation is, if not correct, at least plausible. This is not necessarily the case.

So you just need to begin every Perl program-file with... "shebang ... use strict ... use warnings ..."