If you've ever wanted to learn more about Web protocols so you could build custom client-side tools to automate tasks--or just so you have a better understanding of what's happening behind the scenes--then Web Client Programming with Perl is the book for you. Wong explains HTTP (Hypertext Transfer Protocol) requests and socket calls, then shows how you can use the LWP library for Perl to retrieve Web pages, parse HTML, check whether a server is responding, and more.
On the World Wide Web, people are accustomed to using graphical browsers such as Netscape Navigator or Mosaic as their only interface for visiting remote sites, accessing up-to-date documents, and filling out forms. But graphical browsers can be limiting: the very interactivity that makes them so intuitive to use also makes them clumsy for automating tasks. If you want to get the latest weather report every few hours, track a Federal Express package online, or use a dictionary server repeatedly throughout the day, using your browser to perform the same task over and over can become cumbersome. As with any repetitive task, these applications are best done by writing a script.
Web Client Programming with Perl shows you how to extend scripting skills to the Web. This book teaches you the basics of how browsers communicate with servers and how to write your own customized Web clients to automate common tasks. It is intended for those who are motivated to develop software that offers a more flexible and dynamic response than a standard Web browser.
Using this book, you'll learn how to:
Automate repetitive queries on the Web
Detect broken hyperlinks on your site
Write simple "robots" that traverse hyperlinks across a site, and across the Web in general
This book will be of interest to:
Web administrators who need to automate repetitive tasks or reduce maintenance time
UNIX shell programmers who want to interface their scripts to the Web
Commercial software developers and consultants who need reference material for technical Web specifications and proof-of-concept examples
Most of the examples in this book use Perl, a versatile and portable language that is already familiar to many CGI programmers and UNIX power users. The book does not teach Perl, but the techniques used in the book should be easily followed by anyone with some programming background and can be adapted to whatever language you choose.