Here’s a pattern which took me a while to figure out this past week, and therefore seemed worthy of sharing with you guys.

First, let’s set the situation.  (These are certainly not the only conditions under which you could use this pattern, but it’ll probably be easier to grasp it with a concrete example.)  Let’s say you have a script which you’re going to use to launch your other Perl scripts.  This script (in my example, it’s a bash script, but it could also be a super-minimal Perl script) has exactly one job: set up the Perl environment for all your personal or company modules.  That may even include pointing your $PATH at a different Perl (e.g. one installed via perlbrew or plenv) so you’re not reliant on the system Perl.  Here’s a typical example of what such a (bash) script might look like: