Instead of just diving in headlong into another book, I would suggest that your next step be to apply what you already know and use the books you currently have (and the ones already suggested) as references for when you get stuck. For almost all of the programmers I know, myself included, learning primarily comes by doing, not simply by reading.

Think of little projects to do, regardless of how cheesy they are. They don't have to be grandiose or world-changing. They just have to be opportunities to solidify what you already know and push you to learn what you don't already know. You say you can write a program that traverses a directory? Great! Now, how about a program that traverses a directory and renames files according to a pattern? Has someone else already done it? Absolutely. Does it matter? Hell no. Because it builds on what you already know and pushes you to learn something new. Heck, the first perl program I wrote was a base conversion program. I knew that every other programmer had already written one, but I didn't care. It was new to me, and that's all that mattered. And guess what? I learned something in the process.

One thing you might like doing is writing Perl versions of old games and puzzles. Not only will you learn a lot, but you will also have a lot of fun in the process. What about hangman? Remember MasterMind? What about a program that uses Depth First Search and generates mazes? (Put Mastering Algorithms in Perl to work).

Here's one for ya. Implement Conway's "Doomsday Algorithm" in Perl. In case you don't know, it is a method of determining what day of the week any date in history falls on simply by calculating 5 numbers. It'll be fun and the finished product could be quite useful for a larger program.

Well, you get the idea. I wish you luck in your endeavors.

davidj