CGI + Perl

And yet not. It is an ambiguous blessing that the original CGI persists, adhering to the underside of Web service by the duct tape that is Perl. This point is not missed by Guelich, Gundavaram, and Birznieks, whose advocacy of CGI is both bolstered by the growing applications module base of Perl and tempered by their awareness of CGI's structural limitations. Both new and returning readers of CGI Programming with Perl should browse the last chapter first in order to appreciate the proposed solutions to CGI's greatest sin: its impractical slowness in a world of a million-hits-per-day Web service. The chapter describes CGI-compatible FastCGI and mod_perl technologies that circumvent the process-spawning slowness of the simple CGI. Advanced users might want to skip directly to O'Reilly's fine mod_perl tome, Writing Apache Modules with Perl and C, by Lincoln Stein and Doug MacEachern.

The authors' second pass at CGI pedagogy is a lucid, honest, and expanded account that develops functionality of dynamic Web pages in a rational progression--from HTML client-server and CGI syntax basics to general input/output, forms, e-mail, graphics, and simple database applications, including maintaining client state and data persistence under the otherwise stateless HTTP protocol. The authors offer synopses of cookies, JavaScripting, server security, and XML, all of which are described in detail in other books.

Whether or not neoclassical CGI is fast enough for your purposes--perhaps for guarded intranets--bear in mind that CGI is the standard to which every other Web server has had to respond. The second edition of CGI Programming with Perl is still the best introduction to the classics. --Peter Leopold

Form processing is addressed early on, followed by searching and sorting techniques, illustrations of how to use server-side includes (SSI), and other critical issues. There's also a chapter on using MySQL--an open-source SQL database. In general, if you want to get the most out of this book, you'll be better off having some programming experience, be it in BASIC or C++.

The only element missing from this introductory course is an appendix containing Perl's reserved characters, operators, and functions; instead, this material is presented throughout the book. But CGI Programming 101 is still one of the most efficient ways to get up to speed with Perl CGI. --Stephen W. Plain

Topics covered: Perl variables, CGI environment variables, form processing, data file I/O, searching/sorting, server-side includes (SSI), random number generation, strings, date and time manipulation, HTTP cookies, e-mail processing, securing scripts, Perl modules, database programming, and custom Perl modules.

The first section introduces RenderMan, computer graphics concepts, and mathematics, followed by a section on "Scene Description." This includes chapters on "Describing Models and Scenes in RenderMan" and "Handling Complexity in Photorealistic Scenes."

Sections 3 and 4, "Shading," and "Tricks of the Trade" supply the meat of the book and make it worth the cost of admission. These sections include examples and insight from not only a technical perspective but also a cinematic one. The chapter "Storytelling Through Lighting" should be required reading for beginning computer animation artists.

There are numerous color plates, including some rendering tests from Toy Story. These show the same scene (Andy's room) using different lighting and color palettes, each suggesting a different time of day.

Given the difficulty of the book's subject, 3-D artists or animators with limited technical chops, amateurs, or hobbyists might be better served by something more general. This is, however, an outstanding reference for CG technical directors or anyone with experience in graphics and 3-D programming. It is filled with coding examples used to create RenderMan shaders and case studies citing which techniques were used to create a specific look in, for example, Toy Story or A Bug's Life.

The book has no accompanying CD-ROM, but the publisher maintains a Web site from which code snippets and examples can be downloaded. At first, this may seem inconvenient and merely a way to cut production costs, but it's actually an excellent way to keep the examples current. The field of computer graphics and animation is moving at the speed of light, and the examples and tutorials must move with it. But have no fear--RenderMan is here. --Mike Caputo

The CGI.pm standard allows the site manager to separate data from its HTML markup for use in CGI forms. For example, all the elements in a short drop-down menu of vegetables can be placed in one array, changing this:

to this:

li(['peas','broccoli,'cabbage'])

to be used later throughout a Perl script.

The Official Guide to Programming with CGI.pm is geared toward a reader who is familar enough with Perl to have used modules and knowledgeable about HTML and Web-site design. Stein uses CGI.pm for tables, drop-down menus, guest books, single-page or multipart forms, image maps, and cookies. The author of both the book and Perl library function, Stein provides ample discussion of all of these areas, along with strong code examples. The book ends with a verbose reference guide detailing all of CGI.pm's functions and features, grouped both alphabetically and by topic.

The use of CGI.pm requires a mind shift for Web site managers, but it's one worth making. Instead of tags for 'input' and 'select', CGI.pm uses statements such as "checkbox ()" and "textfield ()," allowing documents to be read easily and updated quickly. --Jennifer Buckendorff