Programming Perl

Programming Perl is not just a book about Perl. It is also a unique introduction to the language and its culture, as you might expect only from its authors. Larry Wall is the inventor of Perl, and provides a unique perspective on the evolution of Perl and its future direction. Tom Christiansen was one of the first champions of the language, and lives and breathes the complexities of Perl internals as few other mortals do. Jon Orwant is the editor of The Perl Journal, which has brought together the Perl community as a common forum for new developments in Perl.

Any Perl book can show you the syntax of Perl's functions, but only this one is a comprehensive guide to all the nooks and crannies of the language. Any Perl book can tell you about typeglobs, pseudohashes, and closures, but only this one can show you how they really work. Any Perl book can tell you that my is faster than local, but only this one can explain why. Any Perl book can have a title, but only this book is affectionately known by all Perl programmers as The Camel.

This 3rd edition of Programming Perl has been expanded to cover version 5.6 of this maturing language. New topics include threading, the compiler, Unicode, and other new features that have been added since the previous edition.

Table of contents

Preface

PART 1: Overview

Chapter 1. An Overview of Perl
Getting Started
Natural and Artificial Languages
An Average Example
Filehandles
Operators
Control Structures
Regular Expressions
List Processing
What You Don't Know Won't Hurt You (Much)

PART 2: The Gory Details

Chapter 2. Bits and Pieces
Atoms
Molecules
Built-in Data Types
Variables
Names
Scalar Values
Context
List Values and Arrays
Hashes
Typeglobs and Filehandles
Input Operators

Chapter 3. Unary and Binary Operators
Terms and List Operators (Leftward)
The Arrow Operator
Autoincrement and Autodecrement
Exponentiation
Ideographic Unary Operators
Binding Operators
Multiplicative Operators
Additive Operators
Shift Operators
Named Unary and File Test Operators
Relational Operators
Equality Operators
Bitwise Operators
C-Style Logical (Short-Circuit) Operators
Range Operator
Conditional Operator
Assignment Operators
Comma Operators
List Operators (Rightward)
Logical and, or, not, and xor
C Operators Missing from Perl

Chapter 4. Statements and Declarations
Simple Statements
Compound Statements
if and unless Statements
Loop Statements
Bare Blocks
goto
Global Declarations
Scoped Declarations
Pragmas

Chapter 5. Pattern Matching
The Regular Expression Bestiary
Pattern-Matching Operators
Metacharacters and Metasymbols
Character Classes
Quantifiers
Positions
Capturing and Clustering
Alternation
Staying in Control
Fancy Patterns

Chapter 6. Subroutines
Syntax
Semantics
Passing References
Prototypes
Subroutine Attributes

Chapter 7. Formats
Format Variables
Footers

Chapter 8. References
What Is a Reference?
Creating References
Using Hard References
Symbolic References
Braces, Brackets, and Quoting

Chapter 9. Data Structures
Arrays of Arrays
Hashes of Arrays
Arrays of Hashes
Hashes of Hashes
Hashes of Functions
More Elaborate Records
Saving Data Structures

Chapter 10. Packages
Symbol Tables
Autoloading

Chapter 11. Modules
Using Modules
Creating Modules
Overriding Built-in Functions

Chapter 12. Objects
Brief Refresher on Object-Oriented Lingo
Perl's Object System
Method Invocation
Object Construction
Class Inheritance
Instance Destructors
Managing Instance Data
Managing Class Data
Summary

Chapter 13. Overloading
The overload Pragma
Overload Handlers
Overloadable Operators
The Copy Constructor (=)
When an Overload Handler Is Missing (nomethod and fallback)
Overloading Constants
Public Overload Functions
Inheritance and Overloading
Run-Time Overloading
Overloading Diagnostics

Chapter 14. Tied Variables
Tying Scalars
Tying Arrays
Tying Hashes
Tying Filehandles
A Subtle Untying Trap
Tie Modules on CPAN

PART 3: Perl as Technology

Chapter 15. Unicode
Building Character
Effects of Character Semantics
Caution, [ren2bold] Working

Chapter 16. Interprocess Communication
Signals
Files
Pipes
System V IPC
Sockets

Chapter 17. Threads
The Process Model
The Thread Model

Chapter 18. Compiling
The Life Cycle of a Perl Program
Compiling Your Code
Executing Your Code
Compiler Backends
Code Generators
Code Development Tools
Avant-Garde Compiler, Retro Interpreter

Chapter 19. The Command-Line Interface
Command Processing
Environment Variables

Chapter 20. The Perl Debugger
Using the Debugger
Debugger Commands
Debugger Customization
Unattended Execution
Debugger Support
The Perl Profiler

Chapter 21. Internals and Externals
How Perl Works
Internal Data Types
Extending Perl (Using C from Perl)
Embedding Perl (Using Perl from C)
The Moral of the Story

PART 4: Perl as Culture

Chapter 22. CPAN
The CPAN modules Directory
Using CPAN Modules
Creating CPAN Modules

Chapter 23. Security
Handling Insecure Data
Handling Timing Glitches
Handling Insecure Code

Chapter 24. Common Practices
Common Goofs for Novices
Efficiency
Programming with Style
Fluent Perl
Program Generation

Chapter 25. Portable Perl
Newlines
Endianness and Number Width
Files and Filesystems
System Interaction
Interprocess Communication (IPC)
External Subroutines (XS)
Standard Modules
Dates and Times
Internationalization
Style

Chapter 26. Plain Old Documentation
Pod in a Nutshell
Pod Translators and Modules
Writing Your Own Pod Tools
Pod Pitfalls
Documenting Your Perl Programs

Chapter 27. Perl Culture
History Made Practical
Perl Poetry

PART 5: Reference Material

Chapter 28. Special Names
Special Names Grouped by Type
Special Variables in Alphabetical Order

Chapter 29. Functions
Perl Functions by Category
Perl Functions in Alphabetical Order

Chapter 30. The Standard Perl Library
Library Science
A Tour of the Perl Library

Chapter 31. Pragmatic Modules
use attributes
use autouse
use base
use blib
use bytes
use charnames
use constant
use diagnostics
use fields
use filetest
use integer
use less
use lib
use locale
use open
use overload
use re
use sigtrap
use strict
use subs
use vars
use warnings

Chapter 32. Standard Modules
Listings by Type
Benchmark
Carp
CGI
CGI::Carp
Class::Struct
Config
CPAN
Cwd
Data::Dumper
DB_File
Dumpvalue
English
Errno
Exporter
Fatal
Fcntl
File::Basename
File::Compare
File::Copy
File::Find
File::Glob
File::Spec
File::stat
File::Temp
FileHandle
Getopt::Long
Getopt::Std
IO::Socket
IPC::Open2
IPC::Open3
Math::BigInt
Math::Complex
Math::Trig
Net::hostent
POSIX
Safe
Socket
Symbol
Sys::Hostname
Sys::Syslog
Term::Cap
Text::Wrap
Time::Local
Time::localtime
User::grent
User::pwent

Chapter 33. Diagnostic Messages

Glossary

Index