http://www.perlmonks.org?node_id=852746
Narveson has asked for the wisdom of the Perl Monks concerning the following question:

We have a monster script that ought to be refactored, but since that's not going to happen, I wanted to at least write some regression tests for how it currently works. One saving grace is that monster.pl does a lot of its work in subroutines. Is there a way I can pull all these subroutine definitions into my test script without running monster.pl?

I can't use use or require or even do, because monster.pl explicitly exits.

Of course I could copy the subs into another file, but I want my test script to run against the current live version.

Of course the subs ought to be placed in one or more modules in separate files, but take my word for it, this is not going to happen.

How does perl -c monster.pl do what it does? Somehow it compiles the code without running it. How can I do the same thing?

Update

Thanks for all these answers!

The key idea seems to be to slurp the file and then wrap the contents in some construct that cancels the run-time phase.

In fact, I've just thought of my own variation (untested):

my $prog_code; my $test_code; # slurp monster.pl into $prod_code # slurp a test suite into $test_code eval "CHECK {$test_code} $prog_code";