Professional PHP Programming

858 Pages·1999·17.86 MB·English

by  Wrox Press

Profe ssional

PHP

Programming

Jesus Castagnetto

Haris h Rawat

Sascha Schumann

Chris Scollo

Deepa k Veliath

Wrox Press Ltd. 

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Professional PH P Programming

© 1999 W rox Press

All rights reserved. No part of this book may be reproduced, stored in a retrieval system
or transmitted in any form or by any means , without the prior written permission of the
publisher, except in the case of brief quotat ions embodied in critical articles or reviews.

The authors and publisher have made every effort in the preparation of this book to ensure
the accuracy of the information. However, t he information contained in this book is sold
without warranty, either express or implie d. Neither the authors, Wrox Press nor its
dealers or distributors will be held liable for any damages caused or alleged to be caused

either directly or indirectly by this book.

Published by W rox Press Ltd
Arden House, 1102 Warwick Road, Acock's Green, Birmingham B27 6BH, UK

Printed in USA
ISBN 1-86 1002-96-3

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Trademark Acknowledgements

Wrox has endeavored to provide trademark information about all the companies and
products mentioned in this book by the ap propriate use of capitals. However, Wrox cannot
guarantee the accuracy of this information.

C redits

Authors Technical Reviewers
Jesus Castagnetto Matt Allen
Harish Rawat Vivek Awasthi
Sascha Schumann Gianluca Baldo
Chris Scollo Robert Baskerville
Deepak Veliath Mathijs Brands

Andy Jeffries

Additional Material Kristian Kohntopp

Mathijs Brands Manuel Lemos

Rod Kreisler Samuel Liddcott

Brian Moon Brad Marsh
Mark Musone Neil Matthews
Julian Skinner Sebastian Moerike-Krauz
Mark Musone
Editors Paul Schreiber
Robert FE Shaw Rick Stones

Soheb Siddiqi Adrian Sill

Julian Skinner Andrew Stopford

Adrian Teasdale
Development Edit or Mark Wilcox

Richard Collins
Design / Layout
Managing Editor Tom Bartlett
Paul Cooper Mark Burdett
Will Fallon
Project Manager Jon Jones

Tony Berry John McNulty

Index Cover Design

Martin Brooks Chris Morris

TEAM FLY PRESENTS
About the Authors

Jesus M. Castagnetto

Jesus M. Castagnetto is a Ph.D. Chemist curr ently working at The Scripps Research
Institute as a Postdoctoral Research Associate in the Metalloprotein Structure and Design

Group (http://www.scripps.edu/research/metallo/), where he is developing the
Metalloprotein Database and Browser (http:/ /metallo.scripps.edu/0) using a
combination of in-house programs, Java appl ets/servlets, SQL databases, and PHP3
server-side scripting. Got his PhD from New York University for research in

computational, synthetic, and physico-chemical studies of small molecule ligand-metal
complexes. Nowadays, he tackles systems th at are a "little" bigger: Metalloproteins.
Bioinformatics and computational modeling of chemical systems are two of his main
areas of interest. In his spare time, (yeah, right!) he hacks awk, PHP, plays way too much

with his PalmPilot, and tries not to hurt anybody while doing Shorinji Kempo, or
swinging his sword wildly in Iaijutsu class.

Harish Rawat

Harish Rawat is a Software Developer at the Oracle Corporation. He has seven years of
experience in systems programming. His technical areas of interest include XML, Java,

and Network protocols.

I would like to thank Arnab and Pankaj for th eir invaluable suggestions in designing the
Shopping Cart Application. I would also like to thank people at Oracle India Development

Center for their encouragement and support throughout the writing process.

Sascha Schumann
Sascha Schumann is a member of the PHP G roup and the Apache
Software Foundation. He currently studies at Gymnasium Letmathe. Sascha is the

architect of many PHP modules (including but not limited to: DBA, Session management,

mcrypt, mhash), has connected PHP with AOLserver, and provides general PHP support
and custom PHP extensions to organizations employing PHP. Sascha also maintains
mhash, which is an open source software for creating cryptological digests (so called

hashes).

Christopher Scollo
Christopher Scollo is the co-founder and pres ident of Taurix, a software development
company based in New Brunswick, New Jers ey. When not developing web applications,
teaching web courses, or drowning in web periodicals, he hikes and eats. (Potatoes are a

passion.) In addition to programming languages, he also enjoys human languages and
speaks English, German, French, and Italian to varying degrees. He lives in Princeton,
New Jersey with his wife, Nicole Bator.

Deepak Veliath

Deepak Veliath is currently working for the Oracle Corporation in Bangalore, India. He
has been following PHP for a year now. Favo rite OS - Linux. When not writing books,
busy making plots to kill editors in their slee p :)

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Table of Contents

I. Introduction
1. About this book
2. Downloading, installing, configuring P HP
3. Programming in a Web environment
II. The Language
4. Variables and data types
5. Operators
6. Expressions and Statements
if ... else ... elseif
switch
while and do ... while
for Error! Bookmark not defin ed.
require and include

exit Error! Bookmark not defined.

7. Functions

How They Work

Passing Arguments

Variable Scope and Lifetime

Nested Functions and Recursion

Assigning Functions to Variables
8. Arrays
Starting Simply
Looping Through an Array
A Sequentially Indexed Arra y
Non-sequentially Indexed Ar rays
A Few Words About next() and prev()
array_walk()
Associative Arrays
Multi-Dimensional Arrays

Sorting Functions

Using Arrays with Form Elements

9. Objects and OOP

Object-Oriented Programming

Defining a Class

Instantiating the Class

Constructors

Inheritance
10. String manipulation and regular expr essions

III. Applying PHP

11. Non-relational databases

What is a database?

Databases and CSV

dbm - a fast, record-based, flat-file database

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Another interface to dbm - DBA
Our telephone book interface
Error! Bookmark not defin ed.
12. SQL DBMS engines
13. Using LDAP

14. Serving XML documents

15. Graphic content creation

16. PHP connectivity

Utilizing TCP

The whois function

The Frontend

Extending the Frontend

Is my domain still available?

A web client
17. Sending E-mail
18. Cookies
What are cookies?
Cookies in PHP
Getting started
Deleting a cookie
Common pitfalls
What is your name?

19. Error handling and debugging

20. Security issues

21. Magic with quotes

What are magic quotes?

Defining the scope

Magic quotes explained

Sybase extension

Applying magic_quotes

Two helper functions
An alternative approach
Summary
22. Templates
IV. Sample Applications

23. A shopping cart application

24. An OO site

V. Advanced Topics

25. Version migration

26. When should I avoid regular expression functions

VI. Appendix

A. Reference

B. Open Source Software

C. PHP in non-UNIX environments

D. Notes on PHP4/Zend

Basic concepts

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The binary compiler
The optimizer
New features in PHP4
PHP4 and overall portability
E. Other Resources

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List of Examples

11-1. edit_form() function

16-1. Initiating a TCP connection

16-2. Exchanging messages with a SMTP server

16-3. whois_request() function

16-4. Simple whois frontend (HTML code)

16-5. Simple whois frontend (PHP code)

16-6. Source code of the simple whois front-end

16-7. Allowing server choice
16-8. Changed PHP code
16-9. a function to tell the TLD
16-10. using an array to store informatio n about whois server
16-11. is_domain_available
16-12. http class framework
16-13. Full http class
16-14. Using the http class
18-1. counting the hits per visitor

18-2. setcookie fails due to sent data before it

18-3. specifying the expire time

18-4. Deleting the cookie username

18-5. deleting and setting a new cookie

18-6. Identifying a visitor

21-1. addslashes()

21-2. output

21-3. output with enabled magic_quotes_sybase

21-4. The ugly way
21-5. automating the conversion process
21-6. using get_magic_quotes_gpc
21-7. using magic_quotes_runtime e ffectively
21-8. applying stripslashes()
21-9. two helper function
21-10. using sprintf()

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Introduction

Over the past years, the Internet has gone from the preserve of academics to the cutting edge of business.

A large part of this has been driven by the growth of the Web, with its graphical browsers and high
media profile. The change from static HTML pa ges to dynamic, user interactive presentations has been
achieved largely by the introduction of scripting technologies.

Working with the usual markup language of a web page, scripting languages enable clients to demand
specific information from their servers, and thei r servers, in turn, to receive important user input in order
to process and display data on demand.

In the forefront of this advancement has been the Open Source community, dedicated in providing web-
based solutions purely for the love of the techno logy itself. Open source is not only about free software
(though not everything is free anyway), but it is about, as the name suggests, being open about the source

of the code.

Having free access to the source means that auth ors are forced to keep to standards. If these are not
maintained, the deviation is labeled a bug, and if the author doesn't fix it, someone else will. Large

numbers of independent programmers being able to understand what a program does, and ensuring that

standards are maintained, prevents the author from being able to exploit the user, as happens in the
commercial software world.

What Does This Book Cover?

PHP, the subject of this book, is an open source server-side scripting language that has taken web-based
development to a new level of sophistication.

In this book we will show you what PHP is, how it simplifies server-side scripting and adds to the

functionality of your web pages.

In particular, we'll be looking at the following a reas:

❑ The PHP language structure and syntax, including its data types, operators, statements and
functions;
❑ The process of installing the scripting e ngine onyour server;

❑ The myriad of PHP modules that greatly enhance its capabilities;

❑ Server Side Programming

❑ Practical case study examples of PHP in action.

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