Beginning Perl

Everything beginners need to start programming with Perl

Perl is the ever-popular, flexible, open source programming
language that has been called the programmers' Swiss army
knife. This book introduces Perl to both new programmers and
experienced ones who are looking to learn a new language. In the
tradition of the popular Wrox Beginning guides, it presents
step-by-step guidance in getting started, a host of try-it-out
exercises, real-world examples, and everything necessary for a Perl
novice to start programming with confidence.

• Introduces Perl to both new programmers and experienced ones
  who want to learn a new language

• Provides a host of real-world applications for today's
  environments so readers can get started immediately

• Covers the new features of Perl but fully applicable to
  previous editions

Beginning Perl provides the information and instruction
you need to confidently get started with Perl.

For Instructors: Classroom and training support material
are available for this book.

Autorentext

Curtis "Ovid" Poe has specialized in Perl since 2000. He is an author, a regular guest speaker at conferences across Europe and the United States, and he wrote the test harness that currently ships with the Perl language.

"This is not your everyday Beginning Perl book. Not only does Ovid provide splendid coverage of Perl's basics and best practices, he also covers modern Perl techniques and modules, where Perl's real power lies. [It] is like being given Batman's utility belt: you have everything you need to do truly amazing things. If Perl were a shark, this book would teach you how to outfit it with lasers."
--Paul Fenwick, Perl Training Australia

Wrox Beginning guides are crafted to make learning programming languages and technologies easier than you think, providing a structured, tutorial format that will guide you through all the techniques involved.

Zusammenfassung
Everything beginners need to start programming with Perl Perl is the ever-popular, flexible, open source programming language that has been called the programmers' Swiss army knife. This book introduces Perl to both new programmers and experienced ones who are looking to learn a new language. In the tradition of the popular Wrox Beginning guides, it presents step-by-step guidance in getting started, a host of try-it-out exercises, real-world examples, and everything necessary for a Perl novice to start programming with confidence.

• Introduces Perl to both new programmers and experienced ones who want to learn a new language
• Provides a host of real-world applications for today's environments so readers can get started immediately
• Covers the new features of Perl but fully applicable to previous editions
  Beginning Perl provides the information and instruction you need to confidently get started with Perl.

For Instructors: Classroom and training support material are available for this book.

Inhalt

Introduction xxiii

Chapter 1: What is Perl? 1

Perl Today 2

Getting Perl 3

Working with Non-Windows Platforms: perlbrew 4

Using Windows 6

The Perl Community 8

IRC 8

PerlMonks 9

Perl Mongers 9

StackOverflow 9

Using perldoc 11

Understanding the Structure of perldoc 11

Getting Started with perldoc 11

Using Tutorials and FAQs 12

Using the perldoc -f function 14

Using a Terminal Window 14

Using the Command Line 15

Creating a Work Directory 16

Creating Hello, World! 18

Writing Your First Program 18

Shebang Lines 21

Summary 22

Chapter 2: Understanding the CPAN 25

CPAN and METACPAN 26

Finding and Evaluating Modules 27

Downloading and Installing 29

CPAN Clients 33

Using the CPAN.pm Client 33

Using the Cpanm Client 35

PPM 36

CPAN::Mini 36

Summary 39

Chapter 3: Variables 41

What is Programming? 42

A Few Things to Note Before Getting Started 43

strict, warnings, and diagnostics 43

The my Function 43

Sigils 44

Identifiers 45

Scalars 46

Strings 47

Numbers 51

Arrays 53

Breaking Down the Code 54

Accessing Elements 55

Iterating over Arrays 58

Hashes 58

Accessing Elements 59

Iterating Over Hashes 60

Adding Data to Hashes 60

Slices 61

Array Slices 62

Hash Slices 62

Context 63

Scalar Context 63

List Context 64

Scope 67

my Variables 67

Package Variables 69

Strict, Warnings, and Diagnostics 72

strict 74

warnings 74

diagnostics 75

Working Without a Net 76

Perl's Built-in Variables 78

$_ 78

%ENV 79

@ARGV 79

Other Special Variables 80

Summary 81

Chapter 4: Working With Data 83

Using Scalars 84

Working with Strings 85

Using String Operators 94

Scalar::Util 97

Numeric Builtins 98

Bitwise Operators 103

Understanding Booleans 103

Assignment Operators 108

Precedence and Associativity 109

Array and List Functions 111

Built-in Array Functions 111

List::Util 116

Built-in Hash Functions 116

delete() 116

exists() 117

keys() 117

values() 117

each() 117

Scoping Keywords 119

my() 119

local() 119

our() 120

state() 120

Summary 121

Chapter 5: Control Flow 125

Using the if Statement 126

Understanding Basic Conditionals 126

else/elsif/unless 128

The Ternary Operator ?: 131

for/foreach loops 132

Arrays 132

Lists 135

C-Style 136

Using while/until Loops 142

Lists 143

last/next/redo/continue 144

Labels 146

Statement Modifiers 147

Types of Statement Modifiers 147

do while/do until 149

given/when 151

Basic Syntax 151

The Switch Module 153

Summary 154

Chapter 6: References 157

References 101 158

Array References 158

Hash References 159

Anonymous References 160

Other References 163

Working with References 166

Debugging 166 C...