This book is about PHP, one of the mostpopular web scripting languages around. It is a book for busy people.Each lesson takes just 10 minutes to work through, so if you havewanted to learn PHP for a while but have never really had the chance,don't put it off any longer!

Who This Book Is For

This book is aimed at those who want tolearn PHP, even if they don't have any previous programming orscripting experience. You can even use this book to learn PHP as afirst programming language if you do not have any previousexperience.

If you have some previous programmingexperience but have not written for the web before, you can use thisbook to learn about the PHP language and how to apply programmingtechniques to the web environment.

This book does not teach you HTML.Although knowledge of HTML is not a prerequisite, having publishedweb pages in the past will be an advantageeven if you do notusually hand-code HTML.

How This Book Is Organized

This book is organized into five parts.

Part I: PHP Foundations

The lessons in Part I introduce thebasic building blocks of the PHP language:

Lesson 1: Getting to Know PHP. Thischapter introduces you to what PHP is all about and gives some simpleexamples to show how PHP is used inside a web page.

Lesson 2: Variables. This chapterexplains how you assign values to variables and demonstrates somesimple expressions.

Lesson 3: Flow Control. This chapterexamines the conditional and looping constructs that allow you tocontrol the flow of a PHP script.

Lesson 4: Functions. This chapterexplains how you can modularize and reuse a frequently used sectionof code as a function.

Part II: Working with Data

The lessons in Part II examine in moredetail the different types of data that can be manipulated by PHP:

Lesson 5: Working with Numbers. Thischapter gives more detailed examples of the numeric manipulation youcan perform in PHP.

Lesson 6: Working with Strings. Thischapter examines the powerful set of string functions that PHPprovides.

Lesson 7: Working with Arrays. Thischapter explains how arrays work and examines the PHP functions thatcan manipulate this powerful data type.

Lesson 8: Regular Expressions. Thischapter shows how to perform complex string manipulation by usingpowerful regular expressions.

Lesson 9: Working with Dates and Times.This chapter examines how to use date and time values in a PHPscript.

Lesson 10: Using Classes. This chapterintroduces you to object-oriented PHP and examines how you define andaccess a class in a script.

Part III: The Web Environment

The lessons in Part III deal with usingPHP specifically in the web environment:

Lesson 11: Processing HTML Forms. Thischapter shows how you use PHP to process user-submitted input from anHTML form.

Lesson 12: Generating Dynamic HTML.This chapter examines some techniques for creating HTML componentson-the-fly from PHP.

Lesson 13: Form Validation. Thischapter examines some techniques for validating user-submitted inputfrom an HTML form.

Lesson 14: Cookies and Sessions. Thischapter shows how to pass data between pages by using PHP sessionsand how to send cookies to a user's browser.

Lesson 15: User Authentication. Thischapter examines some techniques for validating user-submitted inputfrom an HTML form.

Lesson 16: Communicating with the WebServer. This chapter looks at ways in which PHP can interact with aweb server.

Part IV: Using Other Services from PHP

Part IV looks at how PHP cancommunicate with external programs and services:

Lesson 17: Filesystem Access. Thischapter examines the PHP functions that enable you to access thefilesystem.

Lesson 18: Host Program Execution. Thischapter examines the PHP functions that enable you to executeprograms on the host system.

Lesson 19: Using a MySQL Database. Thischapter shows how to use a MySQL database for data storage andretrieval from PHP.

Lesson 20: Database Abstraction. Thischapter explains how you can access a database through an abstractionlayer to make scripts more portable.

Lesson 21: Running PHP on the CommandLine. This chapter shows how you can use PHP as a powerful shellscripting language.

Lesson 22: Error Handling andDebugging. This chapter discusses some techniques for finding andfixing bugs in scripts.

Part V: Configuring and Extending PHP

The final part of the book deals withPHP administration:

Lesson 23: PHP Configuration. Thischapter explains some of the popular configuration options that canbe set at runtime to change the behavior of PHP.

Lesson 24: PHP Security. This chapterdiscusses security issues in PHP scripts and shows how you can useSafe Mode on a shared web server.

Lesson 25: Using PEAR. This chapterintroduces the freely available classes that are available in the PHPExtension and Application Repository.

Versions of Software Covered

At the time of writing, the currentversion of PHP is PHP 5.0.3. Unless otherwise stated, all codeexamples in this book will work with PHP 4.1.0 and higher.

Conventions Used in This Book

This book uses different typefaces todifferentiate between code and regular English, and also to help youidentify important concepts.

Text that you type and text that shouldappear on your screen is presented in monospace type.

It will look like this to mimic the waytext looks on your screen.

Placeholders for variables andexpressions appear in monospace italic font. You should replace theplaceholder with the specific value it represents.

Note

A Note presents interesting pieces ofinformation related to the surroundingdiscussion.

Tip

A Tip offers advice or teaches aneasier way to do something.

Caution

A Caution advises you about potentialproblems and helps you steer clear ofdisaster.

About the Author

Chris Newman is a consultant programmerspecializing in the development of custom web-based databaseapplications to a loyal international client base.

A graduate of Keele University, Chrislives in Stoke-on-Trent, England, where he runs Lightwood ConsultancyLtd., the company he founded in 1999 to further his interest inInternet technology. Lightwood operates web hosting services underthe DataSnake brand and is proud to be one of the first hostingcompanies to offer and support SQLite in addition to PHP as astandard feature on all accounts.

More information on LightwoodConsultancy Ltd. can be found at http://www.lightwood.net