Along with numbers, which were the subject of the previous chapter, another major subject that concerns a wide range of programs is the various paths and locators for finding data:
URLs, URNs, and related strings
Microsoft Windows file and folder names
The URL format in particular has proven so flexible and useful that it has been adopted for a wide range of resources that have nothing to do with the World Wide Web. The toolbox of parsing regular expressions in this chapter will thus prove valuable in a surprising variety of situations.