Is This Book for You? This book's target audience is the person who wants to get an interactive database-based Web site up and running without spending a whole bunch of money on a large stack of books and software. That person might be a technically competent Linux user who is not necessarily a Perl or a CGI whiz; a graphic designer, with a technical bent, who wants to build a Web site without becoming a certified computer whiz; or an MCSE who has heard rumors that there might be another way to do things.Up to now, these folks would have had to purchase four or five thick books and wade through them, picking out the knowledge needed to accomplish necessary tasks. It's likely they would accomplish this in a less than optimal way, picking up some things and missing others, revamping and redoing as they learn new things without being aware of the security considerations necessary to keep their site and computer safe. The goal of this book is to summarize much of the information about Open Source in one place and to do so in a manner that will get the prospective Web developer up and running safely and efficiently, including pointers to other resources when it becomes necessary to have more knowledge than provided here.Our target audience, ideally, would have some familiarity with Unix, some sort of modern programming language (C, FORTRAN, Perl, Pascal, C++, Java--most anything will do), and HTML. The scope here, and the sheer constraints on its size, force us to limit explanations and assume some background knowledge; we touch on a lot of things, enough so that you ought to be able to ask the right questions on a search engine. If you don't have any Unix experience, or if you are not a seasoned programmer, this book can still be useful, with motivation and, perhaps, the purchase of other computer books.What It Will DoIn this book, we introduce you to the pillars of LAMP--Linux, Apache, MySQL, and Perl and PHP--with mod_perl, Embperl, Mason, and WML tossed in for good measure. We are biting off a lot with this book, and this is what we intended to do. We want to cover as much ground as possible and present you with various approaches for programming a Web site with Open Source products. The goal is to point out the part of each of these Open Source approaches that provides the most functionality. Another goal is to make you aware of current techniques and standards: what is easily possible, what might be possible with more work, which tool is appropriate for which task. Just as important is how to discern the things you need from those you don't, or don't need just yet. Not least of all is how to do these things in as secure a fashion as possible. After all, you are opening up your "box" to the world with these techniques and should be wary of those with impure motives.Based on experience, we believe that 80 percent of the utility of any complicated tool is a result of knowing 20 percent of the uses of that tool, whether that tool be software, hardware, mechanical, or electronic. Swiss Army knives are excellent and versatile tools, but most of the time, you just use the blade or the screwdriver. The purpose of this book is to introduce you to that 20 percent--the blade and the screwdriver--that opens up the most functionality and to make you aware of the remaining 80 percent so that you can use the other tools when appropriate. And, to teach you to not use the blade as a screwdriver.Four PartsThe book is divided into four parts:Part I, Structural: Linux, Apache, MySQL, Perl - the structural system foundations on which LAMP is built, and the other programs run.Linux is the operating system this is all based on. We'll touch only lightly on Linux because it's a big subject, but also one that doesn't need to be dealt with much after it's installed.Apache is the Web server software that serves Web pages up to clients, and decides how requests for documents, forms, and so on, will be processed. Chapter 1 talks about the basics of configuring and setting up the Web site.MySQL is an SQL database program. It is "the world's most popular Open Source Database" (it says so on their Web site).Perl is the programming language of choice for interacting with text files, shell scripts, and a million other things. (Python is similar to Perl in functionality; however, we chose Perl for our purposes because we know it better, and like it.)Part II, Static: WML - a set of programs which facilitate building and managing large-scale static Web sites using HTML files.Part III, Dynamic: CGI and mod_perl - the programs with which to build dynamic Web sites.CGI is the tried-and-true way of generating dynamic content.mod_perl is a better, faster and stronger way of generating dynamic content; mod_perl combines two pillars of Open Source: Apache and Perl.Part IV, Embedded: SSI, Embperl, Mason, PHP - embedding programs within HTML pages.SSI is built into Apache. Its job is to preprocess HTML files, turning SSI directives into HTML text; it allows Web programmers to embed executable code into HTML files.Embperl and Mason are Perl modules for building embedded Web content.PHP is another way to embed executable code with HTML files. PHP does what Embperl and Mason do, just differently.So why have so many choices? Read on, gentle reader, and you will discover that a myriad of choices is the Open Source way!Does This Free Software Come with .docs?Of course, with free software, there's free documentation--see linuxdoc and httpd.apache/docs/, to name two. The ultimate documentation, the source code, is available to anyone. (Thus, the Open Source joke, "Use the source, Luke!") Because of the large community of developers and users, there are many newsgroups and discussion forums in which it is likely that someone else has had the same problem as you and has posted a solution. Search using Google (google) and its interface to the USENET archive (groups.google).If you've installed Linux from a distribution, much of the documentation is likely sitting on your hard drive. In an ideal world, you would just read it--that's what we did. Excellent resource though it is, it leaves something to be desired as a learning method. Much of it was written for reference, not instruction. Some of the documentation has not been updated along with the software. (Hey, these folks work for free. In any case, this is a problem to which closed-source software is not immune.)The Old Bait and SwitchFor all our talk of being self-contained, realistically, two books that you can't escape having handy are Hacking Linux Exposed and Unix System Administration Handbook--or , more generically, a book on security and another on system administration. These two are our favorites (hereafter known as HLE and USAH). Each of these subjects is much larger than can be covered here, and both are crucial and unavoidable subjects (but also fun). Get them, read them, grok them.Companion Web SiteIn the course of this book, you'll be shown examples of how to do all the things we discuss on an active Web site (opensourceWebbook/) so that you can see the code and the results, and also be pointed to additional resources. We're striving to be self-contained, but like books, and often tell you which other ones you might want to look at. The entire Web site can also be downloaded from opensourceWebbook/sourcecode/. 020177061XP08092002
by Peter Wainwright
