perl

A good tutorial starts out with something basic and gradually builds on it. This book starts out with three chapters of pure reference material. Granted some of this is a half-assed description of setting up Apache and compiling in mod_perl. I found the docs that come with the Apache and mod_perl source code to be far more useful (and accurate). Then you get this long list of Perl API classes, request object functions, Perl handlers, etc. All of which is wonderfully useful information ... presented at the wrong time ... we have yet to begin writing a useful module.

When we do begin the writing of a module, it isn't a basic, stand-alone module, but a module to add footers to other content. So, the text digresses into a long and technical discussion of the various ways to configure Apache and associate MIME types so that this module will work with documents that we might or might not have on hand (It's just assumed that you have these laying around handy). During this discussion, we get bounced off of other Apache::xyz modules that apparently popped into the author's head in a moment of "As long as we're at it, why don't we throw this in too" inspiration. Wonderful information ... presented at the wrong time.

To give an example: A logical place to start learning Oracle SQL (or any other SQL) would be with the SELECT statement. However, the authors of this book would begin with a detailed discussion of PL/SQL exception handling, a listing of most of the built-in PL/SQL exceptions, and a listing of a number of the built-in Oracle packages. (Recall we were just starting with SQL. But what the heck! PL/SQL is cool, so why not talk about it now? We're going to use it eventually anyway.) Then for your first select statement, you would write something that used a complex join, a correlated subquery, and a few built-in functions. Well, obviously, we can't just throw this extra stuff in there and not talk about it. So we go whirling off into a discussion of complex joins, correlated subqueries and any other tangents that happen to pop into our head. And when it is all said and done, we still don't know how to display the entire contents of the EMP table.

This is a classic of case of making it difficult to see the forrest because of all the trees. The authors of this book have made no attempt to devise a progressive model for building knowledge. Instead, information is dumped on the reader apparently in the order it came to mind. Maybe this is a problem with having multiple authors. Perhaps the parts were written independently, then slung together. That's what it looks like.

I suppose this book will get you to where you are going ... eventually. But I suspect you will spend considerable time flipping back and forth between chapters re-reading and re-re-reading sections in order to re-assemble the information in a somewhat logical pattern; hence the comparison to a 5,000 piece puzzle.

For those who might be wondering: This book assumes you already know the Perl language. If you don't, the "Learning Perl" book is a good starting point (you do NOT want "Programming Perl" at this point). You will probably also want to get some knowledge of HTML and building web documents. And you will probably want to get at least a basic knowledge of custom configuring an Apache installation.

_Writing Apache Modules_ (WAM) is a high quality work, even amongst other O'Reilly books. Few/no typos and articulate writing, very usable index and good content organization, accurate and complete information, top notch Perl code. Yes, only about 5% of the code are in C, but the C API reference is there. I write Perl and C modules and I can use this book for both (though for specific C techniques, you'll probably be better off by reading the Apache developers and apache-modules mailing lists).

I haven't actually read the other mod_perl and developer-oriented Apache books out there but in my opinion this book is still indispensable if you plan to write Apache modules, either in Perl, C, or other languages. Especially if you write for mod_perl, this book is a great complement to the mod_perl guide. Stas' guide focuses on deployment and tuning issues (memory usage, speed, etc) while WAM focuses on the Apache API and how Apache can help you do the job by writing modules.

Personally, _Writing Apache Modules_ is still the most useful reference book to date. It's one that spends the largest amount of time on my desk.

And, oh yes, Amazon gives a good deal on this one ... .

Can't wait for the Apache 2 counterpart.

Not much there for C, although it's not too difficult to make use of the Perl topics and covert them to C, it's more geared towards Perl (much more). That's too bad. Still, it's a good book and is very useful for referencing as well as for people looking to learn more about this topic.