Welcome to the Monastery and the inquisitive and awesome world of Perl, dracut!

You need to be a bit more descriptive here...

Where's the $output variable?

We need more context as to what you're really trying to do. This works:

 $ cat echo.pl 
use warnings;
use strict;

print "hey!\n";
[download]

Then...

perl echo.pl | less
[download]

Output:

hey!
[download]

Are you just wanting to run a Perl script through less or more on the command line? Are you attempting to grab certain variables from a Perl script?