What’s actually installed in that perl library?

A key part of my plan for Upgrading from Perl 5.8 is the ability to take a perl library installed for one version of perl, and reinstall it for a different version of perl.

To do that you have to know exactly what distributions were installed in the original library. And not just which distributions, but which versions of those distributions.

I’ve a solution for that now. It turned out to be rather harder to solve than I’d thought… Continue reading

Upgrading from Perl 5.8


  1. You have a production system, with many different kinds of application services running on many servers, all using the perl 5.8.8 supplied by the system.
  2. You want to upgrade to use perl 5.14.1
  3. You don’t want to change the system perl.
  4. You’re using CPAN modules that are slightly out of date but you can’t upgrade them because newer versions have dependencies that require perl 5.10.
  5. The perl application codebase is large and has poor test coverage.
  6. You want developers to be able to easily test their code with different versions of perl.
  7. You don’t want a risky all-at-once “big bang” upgrade. Individual production installations should be able to use different perl versions, even if only for a few days, and to switch back and forth easily.
  8. You want to simplify future perl upgrades.

I imagine there are lots of people in similar situations.

In this post I want to explore how I’m tackling a similar problem, both for my own benefit and in the hope it’ll be useful to others. Continue reading

Reflections on Perl and DBI from an Early Contributor

The name Buzz Moschetti probably isn’t familiar to you. Buzz was the author of the Perl 4 database for Interbase known as Interperl.

Back in those days Perl 5 was barely a twinkle in Larry’s eye and database interfaces for Perl 4 required building a custom perl binary.

Buzz was one of the four people to get the email on September 29th 1992 from Ted Lemon that started the perldb-interest project which defined a specification that ultimately lead to the DBI. (The other people were Kurt Andersen re informix, Kevin Stock re oraperl, and Michael Peppler re sybperl. I joined a few days later.)

Update: It turns out that it was actually Buzz who sent that original email, Ted just forwarded it on to others, including me. So Buzz can be said to have started the process that led to the DBI!

I hadn’t heard from Buzz for many years until he sent me an email recently.

This is his story: Continue reading