1. Chapter 1 Introduction

   1. Questions and Answers

   2. What Does “Perl” Stand For?

   3. How Can I Get Perl?

   4. How Do I Make a Perl Program?

   5. A Whirlwind Tour of Perl

   6. Exercises

2. Chapter 2 Scalar Data

   1. Numbers

   2. Strings

   3. Perl’s Built-in Warnings

   4. Scalar Variables

   5. Output with print

   6. The if Control Structure

   7. Getting User Input

   8. The chomp Operator

   9. The while Control Structure

   10. The undef Value

   11. The defined Function

   12. Exercises

3. Chapter 3 Lists and Arrays

   1. Accessing Elements of an Array

   2. Special Array Indices

   3. List Literals

   4. List Assignment

   5. Interpolating Arrays into Strings

   6. The foreach Control Structure

   7. Scalar and List Context

   8. <STDIN> in List Context

   9. Exercises

4. Chapter 4 Subroutines

   1. Defining a Subroutine

   2. Invoking a Subroutine

   3. Return Values

   4. Arguments

   5. Private Variables in Subroutines

   6. Variable-Length Parameter Lists

   7. Notes on Lexical (my) Variables

   8. The use strict Pragma

   9. The return Operator

   10. Nonscalar Return Values

   11. Persistent, Private Variables

   12. Exercises

5. Chapter 5 Input and Output

   1. Input from Standard Input

   2. Input from the Diamond Operator

   3. The Invocation Arguments

   4. Output to Standard Output

   5. Formatted Output with printf

   6. Filehandles

   7. Opening a Filehandle

   8. Fatal Errors with die

   9. Using Filehandles

   10. Reopening a Standard Filehandle

   11. Output with say

   12. Exercises

6. Chapter 6 Hashes

   1. What Is a Hash?

   2. Hash Element Access

   3. Hash Functions

   4. Typical Use of a Hash

   5. The %ENV hash

   6. Exercises

7. Chapter 7 In the World of Regular Expressions

   1. What Are Regular Expressions?

   2. Using Simple Patterns

   3. Character Classes

   4. Exercises

8. Chapter 8 Matching with Regular Expressions

   1. Matches with m//

   2. Option Modifiers

   3. Anchors

   4. The Binding Operator, =~

   5. Interpolating into Patterns

   6. The Match Variables

   7. General Quantifiers

   8. Precedence

   9. A Pattern Test Program

   10. Exercises

9. Chapter 9 Processing Text with Regular Expressions

   1. Substitutions with s///

   2. The split Operator

   3. The join Function

   4. m// in List Context

   5. More Powerful Regular Expressions

   6. Exercises

10. Chapter 10 More Control Structures

    1. The unless Control Structure

    2. The until Control Structure

    3. Expression Modifiers

    4. The Naked Block Control Structure

    5. The elsif Clause

    6. Autoincrement and Autodecrement

    7. The for Control Structure

    8. Loop Controls

    9. The Ternary Operator, ?:

    10. Logical Operators

    11. Exercises

11. Chapter 11 Perl Modules

    1. Finding Modules

    2. Installing Modules

    3. Using Simple Modules

    4. Exercise

12. Chapter 12 File Tests

    1. File Test Operators

    2. The stat and lstat Functions

    3. The localtime Function

    4. Bitwise Operators

    5. Exercises

13. Chapter 13 Directory Operations

    1. Moving Around the Directory Tree

    2. Globbing

    3. An Alternate Syntax for Globbing

    4. Directory Handles

    5. Recursive Directory Listing

    6. Manipulating Files and Directories

    7. Removing Files

    8. Renaming Files

    9. Links and Files

    10. Making and Removing Directories

    11. Modifying Permissions

    12. Changing Ownership

    13. Changing Timestamps

    14. Exercises

14. Chapter 14 Strings and Sorting

    1. Finding a Substring with index

    2. Manipulating a Substring with substr

    3. Formatting Data with sprintf

    4. Advanced Sorting

    5. Exercises

15. Chapter 15 Smart Matching and given-when

    1. The Smart Match Operator

    2. Smart Match Precedence

    3. The given Statement

    4. when with Many Items

    5. Exercises

16. Chapter 16 Process Management

    1. The system Function

    2. The exec Function

    3. The Environment Variables

    4. Using Backquotes to Capture Output

    5. Processes as Filehandles

    6. Getting Down and Dirty with Fork

    7. Sending and Receiving Signals

    8. Exercises

17. Chapter 17 Some Advanced Perl Techniques

    1. Trapping Errors with eval

    2. Picking Items from a List with grep

    3. Transforming Items from a List with map

    4. Unquoted Hash Keys

    5. Slices

    6. Exercise

1. Appendix Exercise Answers

   1. Answers to Exercises

   2. Answers to Exercises

   3. Answers to Exercises

   4. Answers to Exercises

   5. Answers to Exercises

   6. Answers to Exercises

   7. Answers to Exercises

   8. Answers to Exercises

   9. Answers to Exercises

   10. Answer to Exercise

   11. Answers to Exercises

   12. Answers to Exercises

   13. Answers to Exercises

   14. Answers to Exercises

   15. Answers to Exercises

   16. Answer to Exercise

2. Appendix Beyond the Llama

   1. Further Documentation

   2. Regular Expressions

   3. Packages

   4. Extending Perl’s Functionality

   5. Some Important Modules

   6. Pragmas

   7. Databases

   8. Other Operators and Functions

   9. Mathematics

   10. Lists and Arrays

   11. Bits and Pieces

   12. Formats

   13. Networking and IPC

   14. Security

   15. Debugging

   16. The Common Gateway Interface (CGI)

   17. Command-Line Options

   18. Built-in Variables

   19. Syntax Extensions

   20. References

   21. Tied Variables

   22. Operator Overloading

   23. Dynamic Loading

   24. Embedding

   25. Converting Other Languages to Perl

   26. Converting find Command Lines to Perl

   27. Command-Line Options in Your Programs

   28. Embedded Documentation

   29. More Ways to Open Filehandles

   30. Locales and Unicode

   31. Threads and Forking

   32. Graphical User Interfaces (GUIs)

   33. And More…

3. Colophon

The animal on the cover of Learning Perl, Fifth Edition is a llama (Lama glama), a relation of the camel native to the Andean range. Also included in this llamoid group is the domestic alpaca and their wild ancestors, the guanaco and the vicu a. Bones found in ancient human settlements suggest that domestication of the alpaca and the llama dates back about 4,500 years. In 1531, when Spanish conquistadors overran the Inca Empire in the high Andes, they found both animals present in great numbers. These llamas are suited for high mountain life; their hemoglobin can take in more oxygen than that of other mammals. Llamas can weigh up to 300 pounds and are mostly used as beasts of burden. A packtrain may contain several hundred animals and can travel up to 20 miles per day. Llamas will carry loads up to 50 pounds, but have a tendency to be short-tempered and resort to spitting and biting to demonstrate displeasure. To other people of the Andes, llamas also provide meat, wool for clothing, hides for leather, and fat for candles. Their wool can also be braided into ropes and rugs, and their dried dung is used for fuel.