If you ask Perl programmers today what book they relied on most when they were learning Perl, you'll find that an overwhelming majority will name Learning Perl--also known affectionately as "the Llama." The first edition of Learning Perl appeared in 1993 and has been a bestseller ever since. Written by two of the most prominent and active members of the Perl community, this book is the quintessential tutorial for the Perl programming language.

Perl began as a tool for Unix system administrators, used for countless small tasks throughout the workday. It has since blossomed into a full-featured programming language on practically every computing platform, and is used for web programming, database manipulation, XML processing, and (of course) system administration--all this while still remaining the perfect tool for the small daily tasks it was designed for. Perl is quick, fun, and eminently useful. Many people start using Perl because they need it, but they continue to use Perl because they love it.

The third edition of Learning Perl has not only been updated for Perl 5.6, but has also been rewritten from the ground up to reflect the needs of programmers learning Perl today. Informed by their years of success at teaching Perl as consultants, the authors have re-engineered the book to better match the pace and scope appropriate for readers trying to get started with Perl, while retaining the detailed discussion, thorough examples, and eclectic wit for which the book is famous.

This edition of the Llama includes an expanded and more gently-paced introduction to regular expressions, new exercises and solutions designed so readers can practice what they've learned while it's still fresh in their minds, and an overall reworking to bring Learning Perl into the new millennium.

Perl is a language for getting your job done. Other books may teach you to program in Perl, but this book will turn you into a Perl programmer.

Table of contents

Preface

1. Introduction
Questions and Answers
What Does "Perl" Stand For?
How Can I Get Perl?
How Do I Make a Perl Program?
A Whirlwind Tour of Perl
Exercises

2. Scalar Data
What Is Scalar Data?
Numbers
Strings
Perl's Built-in Warnings
Scalar Variables
Output with print
The if Control Structure
Getting User Input
The chomp Operator
The while Control Structure
The undef Value
The defined Function
Exercises

3. Lists and Arrays
Accessing Elements of an Array
Special Array Indices
List Literals
List Assignment
Interpolating Arrays into Strings
The foreach Control Structure
Perl's Favorite Default: $_
Scalar and List Context
<STDIN> in List Context
Exercises

4. Subroutines
System and User Functions
Defining a Subroutine
Invoking a Subroutine
Return Values
Arguments
Private Variables in Subroutines
The local Operator
Variable-length Parameter Lists
Notes on Lexical (my) Variables
The use strict Pragma
The return Operator
Exercises

5. Hashes
What Is a Hash?
Hash Element Access
Hash Functions
Typical Use of a Hash
Exercises

6. I/O Basics
Input from Standard Input
Input from the Diamond Operator
The Invocation Arguments
Output to Standard Output
Formatted Output with printf
Exercises

7. Concepts of Regular Expressions
What Are Regular Expressions?
Using Simple Patterns
A Pattern Test Program
Exercises

8. More About Regular Expressions
Character Classes
General Quantifiers
Anchors
Memory Parentheses
Precedence
Exercises

9. Using Regular Expressions
Matches with m//
Option Modifiers
The Binding Operator, =~
Interpolating into Patterns
The Match Variables
Substitutions with s///
The split Operator
The join Function
Exercises

10. More Control Structures
The unless Control Structure
The until Control Structure
Expression Modifiers
The Naked Block Control Structure
The elsif Clause
Autoincrement and Autodecrement
The for Control Structure
Loop Controls
Logical Operators
Exercise

11. Filehandles and File Tests
What Is a Filehandle?
Opening a Filehandle
Fatal Errors with die
Using Filehandles
Reopening a Standard Filehandle
File Tests
Exercises

12. Directory Operations
Moving Around the Directory Tree
Globbing
An Alternate Syntax for Globbing
Directory Handles
Recursive Directory Listing
Exercises

13. Manipulating Files and Directories
Removing Files
Renaming Files
Links and Files
Making and Removing Directories
Modifying Permissions
Changing Ownership
Changing Timestamps
Using Simple Modules
Exercises

14. Process Management
The system Function
The exec Function
The Environment Variables
Using Backquotes to Capture Output
Processes as Filehandles
Getting Down and Dirty with Fork
Sending and Receiving Signals
Exercises

15. Strings and Sorting
Finding a Substring with index
Manipulating a Substring with substr
Formatting Data with sprintf
Advanced Sorting
Exercises

16. Simple Databases
DBM Files and DBM Hashes
Manipulating Data with pack and unpack
Fixed-length Random-access Databases
Variable-length (Text) Databases
Exercises

17. Some Advanced Perl Techniques
Trapping Errors with eval
Picking Items from a List with grep
Transforming Items from a List with map
Unquoted Hash Keys
More Powerful Regular Expressions
Slices
Exercise

A. Exercise Answers

B. Beyond the Llama

Index