Copyright© 1996 by Que Corporation.
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David Medinets has been programming since 1980, when he started with a TRS-80 Model 1. He still fondly remembers the days when he could crosswire the keyboard to create funny-looking characters on the display. Since those days, he has spent time debugging Emacs on UNIX machines, working on VAXen, and messing around with DOS microcomputers. David is married to Kathryn and lives in northwest New Jersey. He runs Eclectic Consulting and has coauthored Special Edition Using Lotus Notes Release 4 (Que), Special Edition Using Turbo C++ 4.5 for Windows (Que), Microsoft Office 95 Unleashed (Sams), and Visual Basic Unleashed (Sams), among others. David can be reached at medined@planet.net.
I'd like to thank all of the people at Que for making this book possible. You'll find their names listed on the Credits page, so I won't list them all here. Susan Ross Moore deserves special thanks for figuratively watching over my shoulder as I worked. Her comments definitely made this a better book. Al Valvano was instrumental in making sure that everything came together at the proper time.
My wonderful wife deserves some thanks for letting me hang out on the Internet at all hours of the day and night while I did research for this book.
While writing this book, I have gleaned information from many books, articles, and Web resources. Where a particular item greatly influenced my thinking, I have given credit in the appropriate section.
Dale Bewley helped to create Chapter 19, "What Is CGI?"-Thanks Dale!
And of course, no Perl author should forget to thank: Larry Wall for creating Perl in the first place; Tom Christiansen for his remarkable contributions to the Perl community; and Randal Schwartz for his Learning Perl book which every Perl programmer seems to have read.
Thanks,
David
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This book is based on the learn-by-doing principle because I believe that simply reading about a subject makes it harder to learn. After all, you don't read about putting together a jigsaw puzzle; you put the puzzle together yourself! Programming is the same way. You must actually run some programs in order to really understand the concepts.
Perl 5 By Example will teach you how to use the Perl programming language by showing examples that demonstrate the concepts being discussed. The examples are designed to give you a chance to experiment-which in turn should clarify the material.
Additional information and errata pages can be found at http://www.mtolive. com/pbe/index.html.
The topics are covered in a straightforward, nontechnical manner, which allows you to quickly understand the fundamental principles. After the main topic of each chapter is introduced, subtopics are explored in their own sections. Each section has its own Perl examples with explanations given in pseudocode.
Each chapter finishes with review questions of varying difficulty based on the material in that chapter. The answers usually come from the text or are deducible from the text, but occasionally you might need to experiment a little. Try to answer the questions at all difficulty levels. If you get stuck turn to the answers provided in Appendix A. Also, look at the summary sections after reading each chapter and return to them frequently. After you've gone through several chapters, you'll begin to understand more often the reason why a concept was illustrated or a question was asked. Returning to questions that frustrated you earlier and realizing that now you know the answers can be a big confidence builder.
Perl 5 By Example should be read by anyone seeking to learn Perl. If you don't know any other programming languages, Chapters 2 through 7 will give you a solid introduction to the basics. If you already know another language, then skip Chapters 2 through 7 to see how Perl differs from other languages and start with Chapter 8, "References."
This book follows a simple format. Each chapter contains a single topic-usually. First, you read about the topic and then you see examples that let you work directly with Perl to understand how the concepts can be applied to a program. At the end of each chapter is a summary, followed by review questions and exercises.
This approach is designed to serve a broad range of readers from novice to advanced. If you've never programmed before, the learn-by-doing approach will help you move quickly and easily though this book. If you have programming experience, you'll find plenty of material to refine and enhance what you already know, and to give you a solid understanding of how Perl works.
In order to effectively use this book you need two things. You need a working copy of Perl 5. And you need a text editor. That's it.
You can use the examples in this book with just about any hardware and operating system. I'm not sure that they would work on an Amiga system but other than that you should be able to run every example.
There are several ways to use this book. One obvious method is to begin at the first page and proceed in order until t