Chapter 2. Web Basics

Three things made the Web possible: HTML for encoding documents, HTTP for transferring them, and URLs for identifying them. To fetch and extract information from web pages, you must know all three—you construct a URL for the page you wish to fetch, make an HTTP request for it and decode the HTTP response, then parse the HTML to extract information. This chapter covers the construction of URLs and the concepts behind HTTP. HTML parsing is tricky and gets its own chapters later, as does the module that lets you manipulate URLs.

You'll also learn how to automate the most basic web tasks with the LWP::Simple module. As its name suggests, this module has a very simple interface. You'll learn the limitations of that interface and see how to use other LWP modules to fetch web pages without the limitations of LWP::Simple.