Apache Module Development in C

Last modified: Wednesday, 31 December 1969 19:00 -0500

Who Should Read This Book, and Why?

Why should you buy any particular computer book? I mean, there are a lot of topics they cover, there are generally lots of titles for each topic, and the books aren't cheap. This page is intended to help you decide whether you should buy this book. Much of the text that follows comes directly from the book's introduction, so you're seeing pretty much the same thing you would if you were trying to make the decision by thumbing through it in a bookstore.

Who Should Read This Book

Since this book is about writing software, the intended audience is primarily programmers and software engineers. And since the Apache Web server is written in ANSI C, that is the language supported for add-on modules and what all of the examples in the book use. The reader should be comfortable reading and writing in C; fluency is even better.

Writing an add-on module for the Apache HTTP server is a fairly advanced topic, and so one of the assumptions made throughout this book is that the reader is familiar and comfortable with using the Web server software package itself. Familiarity with the configuration directives, scoping, .htaccess files, security features, and other aspects of operating a Web site with Apache is a must.

Why Write a Module?

Since modules are actually bits of software that are linked into the running server, they have an advantage over the alternative (i.e., external applications invoked by the server at need, like CGI scripts). For one thing, their performance tends to be better than that of an equivalent CGI script; for another, they have access to the full range of the Apache API and the request processing sequence. There is no per-use startup or activation performance penalty, since the code is already running.

The Apache Web server is a fairly complex beast, featureful and pervasive. Writing a module for it must therefore be an involved and arduous task, right? Well, no, not necessarily. In fact, depending upon what you want to do, you might be able to have your module built and running in a day. (More involved functionality may take longer, of course.) The role of a module is to be available to perform its task(s) at the appropriate times during the server's operation; these points at which modules can get involved are called phases, and they are described in later chapters. The complexity of a module is directly related to the number and types of phases in which it is involved; the simplest module may be only a few lines long, while the most complex may well require hundreds of lines of code to accomplish its purpose.

This is the official companion Web site for the Apache Module Development in C book being written by Ken Coar.

The book is still under development, so if you have a particular topic you'd like to see covered in the book, or have suggestions or comments, please do send me mail. The address is <Author@Apache-Modules.Com>.