Perl Debugged

*Surpasses archaic debugging practices. *Introduces advanced debugger topics such as customization, optimization and extension. *Serves as a valuable resource for developing and deploying rock-solid Perl applications. *There is no direct competition for an advanced and comprehensive debugging book.

Most Perl programmers know about the Perl debugger--the nifty little built-in utility that you can use to fully debug any programs that you write. Inside the interactive debugger environment, you're prompted for commands that let you examine your source code, set breakpoints, dump out function call stacks, change values of variables, and much more. It's so convenient that some programmers run it just to test out Perl constructs as they create a program. But although it's on their radar, not many Perl programmers take the time to master the debugger. That's where the Perl Debugger Pocket Reference comes in. This little book provides a quick and convenient path to mastery of the Perl debugger and its commands. Written by a core member of the Perl debugger development team, it's an ideal quick reference to debugger commands, as well as a detailed tutorial on how to get started. The Perl Debugger Pocket Reference provides complete coverage in a conveniently small package. Maybe you write code so clean you never have to look at it twice. Or perhaps you'd rather focus your energies on writing clean code, rather than learning about the debugger. But if you need to learn about the Perl debugger in a hurry, the Perl Debugger Pocket Reference is the book you'll want to have close by. And you can always keep a copy on hand to share with programmers who need it more than you do. O'Reilly's Pocket References have become a favorite among programmers everywhere. By providing a wealth of important details in a concise, well-organized format, these handy books deliver just what you need to complete the task at hand. When you've reached a sticking point in your work and need to get to a solution quickly, the new Perl Debugger Pocket Reference will get you back on the right track.

"Jocelyn Brooke is a great writer. . . . If you care enough for literature, seek out The Scapegoat."--Elizabeth Bowen "Brooke marked out his magical, personal kingdom, different from any other writer."--Anthony Powell

"Debugging Perl" explains how to best use the features of Perl to create functions and reuse existing code to develop applications that eliminate the problems before they start. Warnings caution against common or easy-to-make programming errors.

A guide to getting the most out of Perl covers such topics as productivity hacks, user interaction, data munging, working with modules, object hacks, and debugging.

Take the next step toward Perl mastery with advanced concepts that make coding easier, maintenance simpler, and execution faster. Mastering Perl isn't a collection of clever tricks, but a way of thinking about Perl programming for solving debugging, configuration, and many other real-world problems you’ll encounter as a working programmer. The third in O’Reilly’s series of landmark Perl tutorials (after Learning Perl and Intermediate Perl), this fully upated edition pulls everything together and helps you bend Perl to your will. Explore advanced regular expressions features Avoid common problems when writing secure programs Profile and benchmark Perl programs to see where they need work Wrangle Perl code to make it more presentable and readable Understand how Perl keeps track of package variables Define subroutines on the fly Jury-rig modules to fix code without editing the original source Use bit operations and bit vectors to store large data efficiently Learn how to detect errors that Perl doesn’t report Dive into logging, data persistence, and the magic of tied variables

Programming on the Web today can involve any of several technologies, but the Common Gateway Interface (CGI) has held its ground as the most mature method--and one of the most powerful ones--of providing dynamic web content. CGI is a generic interface for calling external programs to crunch numbers, query databases, generate customized graphics, or perform any other server-side task. There was a time when CGI was the only game in town for server-side programming; today, although we have ASP, PHP, Java servlets, and ColdFusion (among others), CGI continues to be the most ubiquitous server-side technology on the Web.CGI programs can be written in any programming language, but Perl is by far the most popular language for CGI. Initially developed over a decade ago for text processing, Perl has evolved into a powerful object-oriented language, while retaining its simplicity of use. CGI programmers appreciate Perl's text manipulation features and its CGI.pm module, which gives a well-integrated object-oriented interface to practically all CGI-related tasks. While other languages might be more elegant or more efficient, Perl is still considered the primary language for CGI.CGI Programming with Perl, Second Edition, offers a comprehensive explanation of using CGI to serve dynamic web content. Based on the best-selling CGI Programming on the World Wide Web, this edition has been completely rewritten to demonstrate current techniques available with the CGI.pm module and the latest versions of Perl. The book starts at the beginning, by explaining how CGI works, and then moves swiftly into the subtle details of developing CGI programs.Topics include: Incorporating JavaScript for form validation Controlling browser caching Making CGI scripts secure in Perl Working with databases Creating simple search engines Maintaining state between multiple sessions Generating graphics dynamically Improving performance of your CGI scripts

Perl was originally written by Larry Wall while he was working at NASA’s Jet Propulsion Labs. Larry is an Internet legend, known not just for Perl, but as the author of the UNIX utilities rn, one of the original Usenet newsreaders, and patch, a tremendously useful tool that takes a list of differences between two files and allows you to turn one into the other. The term patch used for this activity is now widespread. Perl started life as a “glue” language for Larry and his officemates, allowing one to “stick” different tools together by converting between their various data formats. It pulled together the best features of several languages: the powerful regular expressions from sed (the Unix stream editor), the patte- scanning language awk, and a few other languages and utilities. The syntax was further made up out of C, Pascal, Basic, Unix shell languages, English, and maybe a few other elements along the way. While Perl started its life as glue, it is now more often likened to another handy multiuse tool: duct tape. A common statement heard in cyberspace is that Perl is the duct tape that holds the Internet together.