Tài liệu Chapter 1:Introduction- Web Client Programming with Perl doc

Chapter 1:Introduction- Web Client

Programming with Perl

So what does Web client programming mean, and what do you need to learn

to do it?

A web client is an application that communicates with a web server, using

Hypertext Transfer Protocol (HTTP). Hypertext Transfer Protocol is the

protocol behind the World Wide Web. With every web transaction, HTTP is

invoked. HTTP is behind every request for a web document or graphic,

every click of a hypertext link, and every submission of a form. The Web is

about distributing information over the Internet, and HTTP is the protocol

used to do so.

Most web users never think about HTTP, just as most TV viewers don't

think about how video images get from the studio to their home. But this

book is not for the average web user. This book is for people who want to do

something that available web software won't let them do.

Why Write Your Own Clients?

With the proliferation of available web browsers, you might wonder why

you would want to write your own client program. The answer is that by

writing your own client programs, you can leap beyond the preprogrammed

functionality of a browser. For example, the following scenarios are all

possible:

 An urgent document is sent out via Federal Express, and the sender

wants to know the status of the document the moment it becomes