Preface

Welcome to the fourth edition of Learning Perl.

If you're looking for the best way to spend your first 30 to 45 hours with the Perl programming language, you've found it. In the pages that follow, you'll find a carefully paced introduction to the language that is the workhorse of the Internet, as well as the language of choice for system administrators, web hackers, and casual programmers around the world.

We can't give you all of Perl in just a few hours. The books that promise this are probably fibbing a bit. Instead, we've carefully selected a useful subset of Perl for you to learn, good for programs from one to 128 lines long, which end up being about 90% of the programs in use out there. And when you're ready to go on, you can get the Alpaca book, which picks up where this book leaves off. We've also included a number of pointers for further education.

Each chapter is small enough so you can read it in an hour or two. Each chapter ends with a series of exercises to help you practice what you've learned, with the answers in Appendix A for your reference. Thus, this book is ideally suited for a classroom "Introduction to Perl" course. We know this because the material for this book was lifted almost word-for-word from our flagship "Learning Perl" course delivered to thousands of students around the world. However, we've designed the book for self-study as well.

Perl lives as the "toolbox for Unix," but you don't have to be a Unix guru or a Unix user to use this book. Unless otherwise noted, everything we're saying applies equally well to Windows ActivePerl from ActiveState and most other modern implementations of Perl.

Though you don't need to know about Perl to begin reading this book, we recommend that you have familiarity with basic programming concepts such as variables, loops, subroutines, and arrays, and the all-important "editing a source code file with your favorite text editor." We don't spend any time explaining those concepts. We're pleased that we've had many reports of people successfully picking up Learning Perl and grasping Perl as their first programming language, but we can't promise the same results for everyone.