http://www.perlmonks.org?node_id=1203327

likbez has asked for the wisdom of the Perl Monks concerning the following question:

This is kind of topic that previously was reserved to Cobol and PL/1 forums ;-) but now Perl is almost 30 years old and it looks like the space for Perl archeology is gradually opening ;-).

I got a dozen of fairly large scripts (several thousand lines each) written in a (very) early version of Perl 5 (below Perl 5.6), I now need:

1. Convert them to use strict pragma. The problem is that all of them share (some heavily, some not) information from main program to subroutines (and sometimes among subroutines too) via global variables in addition to (or sometimes instead of) parameters. Those scripts mostly do not use my declarations either.

So I need to map variables into local and global namespaces for each subroutine (around 40 per script; each pretty small -- less then hundred lines) to declare them properly.

As initial step I just plan use global variable with namespace qualification or our lists for each subroutine. Currently I plan to postprocess output of perl -MO=Xref old_perl_script.pl

and generate such statement. Is there a better way ?

2. If possible I want to split the main namespace into at least two chunks putting all subroutines into another namespace, or module. I actually do not know how to export subroutines names into other namespace (for example main::) when just package statements is used in Perl as in example below. Modules do some magic via exporter that I just use but do not fully understand. For example if we have

#main_script ... ... ... x:a(1,2,3); ... ... ... package x; sub a {...) sub b {...} sub c {...} package y; ... ... ...
How can I access subs a,b,c without qualifying them with namespace x from the main:: namespace?

3. Generally this task looks like a case of refactoring. I wonder, if any Perl IDE has some of required capabilities, or are there tools that can helpful.

My time to make the conversion is limited and using some off the shelf tools that speed up the process would be a great help.

Any advice will be greatly appreciated.