Table of Contents

Foreword Preface 1. Introduction What Should You Know Already? What About All Those Footnotes? What's with the Exercises? What if I'm a Perl Course Instructor? 2. Building Larger Programs The Cure for the Common Code Inserting Code with eval Using do Using require require and @INC The Problem of Namespace Collisions Packages as Namespace Separators Scope of a Package Directive Packages and Lexicals Exercises 3. Introduction to References Performing the Same Task on Many Arrays Taking a Reference to an Array Dereferencing the Array Reference Dropping Those Braces Modifying the Array Nested Data Structures Simplifying Nested Element References with Arrows References to Hashes Exercises 4. References and Scoping More than One Reference to Data What if That Was the Name? Reference Counting and Nested Data Structures When Reference Counting Goes Bad Creating an Anonymous Array Directly Creating an Anonymous Hash Autovivification Autovivification and Hashes Exercises 5. Manipulating Complex Data Structures Using the Debugger to View Complex Data Viewing Complex Data with Data::Dumper Storing Complex Data with Storable The map and grep Operators Using map Applying a Bit of Indirection Selecting and Altering Complex Data Exercises 6. Subroutine References Referencing a Named Subroutine Anonymous Subroutines Callbacks Closures Returning a Subroutine from a Subroutine Closure Variables as Inputs Closure Variables as Static Local Variables Exercise 7. Practical Reference Tricks Review of Sorting Sorting with Indices Sorting Efficiently The Schwartzian Transform Recursively Defined Data Building Recursively Defined Data Displaying Recursively Defined Data Exercises 8. Introduction to Objects If We Could Talk to the Animals... Introducing the Method Invocation Arrow The Extra Parameter of Method Invocation Calling a Second Method to Simplify Things A Few Notes About @ISA Overriding the Methods Starting the Search from a Different Place The SUPER Way of Doing Things What to Do with @_ Where We Are So Far... Exercises 9. Objects with Data A Horse Is a Horse, of Course of Course-or Is It? Invoking an Instance Method Accessing the Instance Data How to Build a Horse Inheriting the Constructor Making a Method Work with Either Classes or Instances Adding Parameters to a Method More Interesting Instances A Horse of a Different Color Getting Your Deposit Back Don't Look Inside the Box Faster Getters and Setters Getters That Double as Setters Restricting a Method to Class-Only or Instance-Only Exercise 10. Object Destruction Beating a Dead Horse Indirect Object Notation Additional Instance Variables in Subclasses Using Class Variables Weakening the Argument Exercise 11. Some Advanced Object Topics UNIVERSAL Methods Testing Your Objects for Good Behavior AUTOLOAD as a Last Resort Using AUTOLOAD for Accessors Creating Getters and Setters More Easily Multiple Inheritance References to Filehandles Exercise 12. Using Modules Sample Function-Oriented Interface: File::Basename Selecting What to Import Sample Object-Oriented Interface: File::Spec A More Typical Object-Oriented Module: Math::BigInt The Differences Between OO and Non-OO Modules What use Is Doing Setting the Path at the Right Time Importing with Exporter @EXPORT and @EXPORT_OK Exporting in a Primarily OO Module Custom Import Routines Exercise 13. Writing a Distribution Starting with h2xs Looking at the Templates The Prototype Module Itself Embedded Documentation Controlling the Distribution withMakefile.PL Alternate Installation Locations (PREFIX=...) Trivial make test Trivial make install Trivial make dist Using the Alternate Library Location Exercise 14. Essential Testing What the Test Harness Does Writing Tests with Test::Simple Writing Tests with Test::More Conditional Tests More Complex Tests (Multiple Test Scripts) Testing Things That Write to STDOUT and STDERR Exercise 15. Contributing to CPAN The Comprehensive Perl Archive Network Getting Prepared Preparing Your Distribution Uploading Your Distribution Announcing the Module Testing on Multiple Platforms Consider Writing an Article or Giving a Talk Exercise Appendix. Answers to Exercises Index

About the Author

Randal L. Schwartz is a two-decade veteran of the software industry. He is skilled in software design, system administration, security, technical writing, and training. Randal has coauthored the "must-have" standards: Programming Perl, Learning Perl, Learning Perl for Win32 Systems, and Effective Perl Learning, and is a regular columnist for WebTechniques, PerformanceComputing, SysAdmin, and Linux magazines.He is also a frequent contributor to the Perl newsgroups, and has moderated comp.lang.perl.announce since its inception. His offbeat humor and technical mastery have reached legendary proportions worldwide (but he probably started some of those legends himself). Randal's desire to give back to the Perl community inspired him to help create and provide initial funding for The Perl Institute. He is also a founding board member of the Perl Mongers (perl.org), the worldwide Perl grassroots advocacy organization. Since 1985, Randal has owned and operated Stonehenge Consulting Services, Inc. Randal can be reached for comment at merlyn@stonehenge.com or (503) 777-0095, and welcomes questions on Perl and other related topics. Tom Phoenix has been working in the field of education since 1982. After more than thirteen years of dissections, explosions, work with interesting animals, and high-voltage sparks during his work at a science museum, he started teaching Perl classes for Stonehenge Consulting Services, where he's worked since 1996. Since then, he has traveled to many interesting locations, so you might see him soon at a Perl Mongers' meeting. When he has time, he answers questions on Usenet's comp.lang.perl.misc and comp.lang.perl.moderated newsgroups, and contributes to the development and usefulness of Perl. Besides his work with Perl, Perl hackers, and related topics, Tom spends his time on amateur cryptography and speaking Esperanto. His home is in Portland, Oregon.

Reviews

"Here we have a typical O'Reilly book, with all the humor that makes them so popular. The book is littered with examples trying to bring a lighter side to what is often a pretty heavy subject." - Linux Magazine