The tutorial guides you through the construction of a simple, security-related class that performs some basic security functions for a web site: checking user logons.

Learn how authentication, cookies, and sessions can add security and a personal touch to your site.

Showing how to store and retrieve binary data in a MySQL database by using PHP.

Harry takes us one step further into the world of Web Services. Here he explains how to build your own Web Service - a news feed - using PHP and XML-RPC.

A description in plain English of what classes are, and how they can make your project easier to complete and extend.

Code Injection is a term used when code is injected straight into a program/script from an outside source for execution at some point in time.

A good programmer makes her code look so simple and comprehensible that any other programmer can understand it and appreciate it.

This article introduces a toolkit designed specifically for manipulating configuration files, thereby reducing the number of lines of code needed to read and modify application variables. This toolkit is written in PHP and implemented as a class, suitable for use in any PHP-based application and accessible via standard OO techniques.

Take a look at the PEAR database abstraction layer, one of the coolest PHP widgets out there.

A tutorial on using PHP3 and MySQL to develop database enabled applications for websites.

The purpose of this article is to show you how to encrypt and decrypt information with GnuPG using PHP.

This article teaches you to handle errors in an elegant manner, and looks at how to handle PHP script errors as well as passing around your own errors with the PEAR module: PEAR_Error.

PHP comes with a full-featured file and directory manipulation API that allows you (among other things) to view and modify file attributes, read and list directory contents, alter file permissions, retrieve file contents into a variety of native data structures, and search for files based on specific patterns. This file manipulation API is both powerful and flexible - two characteristics that will endear it to any developer who's ever had to work with file manipulation commands.

This second segment of the tutorial on the PHP filesystem API takes you into deeper waters, showing you how to copy, delete and rename files; scan directories; work with uploaded files over HTTP; perform pattern matches on file names; and read and write to processes instead of files.

PHP's Mail() function is a great way to send mail using a simple and standard interface that hides the complexity and quirks of various system programs that are responsible for sending mail. This tutorial will introduce you to the basics of sending mail from PHP scripts.

A series of tutorials on using PHP to access GIS mapping information. The tutorials start with the basics, build on them, and provide many examples for more complex functions.

Provides detailed, step-by-step information on compiling PHP as an Apache 2.0 shared module on a Linux system.

Covers the basics on how to do virtual includes in a PHP file.

Conditional probability -- the probability of observing one event as a result of having observed another event -- is a potentially important factor in designing intelligent Web applications. Paul Meagher introduces Bayesian inference by discussing the basic mathematical concepts involved and demonstrating how to implement the underlying conditional probability calculations using PHP.

This tutorial is designed to guide through the initial steps of setting up Apache, MySQL, and PHP on Linux.

An indepth article that offers a step by step guide on setting up a home server for website development and testing.

An excellent overview of PHP image functions, including source code and interactive online examples.

PHP and GIMP tutorials.

PHP Tutorial on magic quotes, why they are bad, and how to get around them.

Open Source licensing for PHP scripts. Open Source means that your software is entirely free for use, to anyone, and any user may modify the software to fit his own needs. To launch an open source application, you have to apply the GNU GPL License.

This tutorial steps through the POSIX-compliant regular expression functions in PHP in a straightforward manner.

About the various security concerns and mistakes people make when developing, and their solutions.

Tutorial for feedback, bug report, contact PHP forms includes all copy and paste code.

PHP introduction for web designers by Matt Mullenweg.

Complete and hyperlinked manual documents and explains all elements of PHP. Includes FAQ section and user comments.

The lessons provided in this PHP/MySQL tutorial are short and simple. You'll learn to create and manipulate a simple database of names and birthdates.

A basic PHP tutorial for beginners. It includes printing, variables, constants, math, strings, files, functions, arrays, and several other key points of PHP.

This tutorial is aimed at users who have no previous experience with programming in PHP or any other programming language.

A very thorough tutorial that starts from the beginning.

A PHP tutorial that covers all the basics of PHP. It is geared towards web developers with little or no PHP experience.

Three-part tutorial covers installation, basic scripts, forms, and advanced topics.

Database transactions are important for data reliability and consistency. Used properly, they can prevent many types of errors. Used improperly, they can cause many other kinds of errors. Kimberlee Jensen demonstrates using transactions with PHP well.

Article on perl compatible regular expressions. Describes the basics as well as PCRE's special features such as ungreedy matching, lookaheads or the evaluation modifier.

A wikibook about programming in PHP. Also provides external links for more information.

Tutorial explains how to implement the phpCache script and use it to keep your database server load low.

Article describes three ways to make your URLs search engine friendly using PHP.

Describes how to send XHTML with the correct mime type safely using PHP. Includes the ability to "fall back" to HTML if the viewing web-browser does not support XHTML.

By the end of this tutorial, you'll have a better understanding of what classes are and what they are good for. Classes can be very powerful when used right and can save you a lot of work (and typing) in the long run.

In contrast with other open source languages like Perl and Python, PHP lacks a robust community effort to develop a math library. This article provides an example of a PHP math library called SimpleLinearRegression that demonstrates a general approach that can be used to develop PHP math libraries.

Windows Installation Guide for Apache + PHP + MySQL + PHPMyAdmin.

This tutorial will show you how to produce static html pages using PHP. This is important if you want the benefits of using PHP to build sections of a site where the content of the pages doesn't change very often.

The future for applying Object Oriented Programming in PHP looks bright, when we look at the new OO features that PHP 5/Zend Engine 2 brings us. With the right tools, all you need is the knowledge. This article will try to explain what objects really are and how they can be recognized, and it will familiarize you with the "3 Pillars" that form the foundation of Object Oriented Programming: Encapsulation, Inheritance and Polymorphism.

Show how to use 'php includes' inside a template.

Though it's easy to create sites in PHP, it's not immune to sloppy coding. Clancy Malcolm explains how to recognize and fix potential security holes.

Luis Yordano Cruz demonstrates three-tier PHP application design with PEAR::DB_DataObject, Smarty, and PHP 5. The article assumes that you have some familiarity with HTML, Smarty, PEAR::DB_DataObject, MySQL, and PHP 5.

BB code is a simple set of instructions that provide rules as to how a piece of text should be formatted. In this hands-on tutorial, Stoyan explains the basics that every developer should know about the use of BB code in PHP applications.

Learn how to set and read cookies using the PHP scripting language.

This tutorial explains the usage of the Simple XML extension new to PHP 5. It provides examples of reading and querying XML data.