If you bought the e-book version of Programming Perl, 4th Edition, you should be able to get the updated copy of it. In that, we fix various typos and thought errors reported through the errata system. And, we refresh the bits so all those stale 1s and 0s are replaced with new ones.
You can register your paper copy of any O’Reilly book to get a discount on the e-version. Better than that, you can connect your Dropbox account (referral link) to allow O’Reilly to automatically sync your purchases and updates.