What This Book Offers
The bulk of this book consists of examples of the behind-the-scenes programming used to create and maintain large web sites. Most of the programming is in Perl, with the remainder consisting of Unix command-line utilities and shell scripting.
Accompanying the examples are in-depth explanations intended for an audience that is technically adept, but not expert at programming. Along the way are pointers to more detailed explanatory material, whether in manpages (more about those in the next chapter), on the Web, or in other books. The overall approach is that of a tutorial, progressing from simple concepts in the early chapters to more complex ones later on.
All of the examples are based on actual, in-the-trenches programming. Although some have been rewritten to make them suitable as teaching devices, at the core each represents a particular solution for a particular set of circumstances—and not necessarily the only solution, or even the best one. “There’s more than one way to do it” is the Perl community’s motto. There is no “correct” way to do anything in Perl, except in the sense that Larry Wall described in the preface to Programming Perl, where he wrote that “A Perl script is `correct’ if it gets the job done before your boss fires you.”
All of the examples in this book have met that standard successfully,
at least for certain values of job and
boss and fires, but beyond that you probably shouldn’t assume too much. In particular, do not think of these examples ...