Learning Perl, 5th Edition

Chapter 11. Perl Modules

There is a lot more to Perl than what we’re able to show you in this book, and there are a lot of people doing a lot of interesting things with Perl. If there is a problem to solve, then somebody has probably already solved it and made their solution available on the Comprehensive Perl Archive Network (CPAN), which is a worldwide collection of servers and mirrors containing thousands of modules of reusable Perl code.

We’re not going to teach you how to write modules here: you’ll have to get that from the Alpaca book. In this chapter, we’ll show you how to use modules that already exist.

Finding Modules

Modules come in two types: those that come with Perl and that you should have available to you, and those that you can get from CPAN to install yourself. Unless we say otherwise, the modules that we discuss come with Perl.

To find modules that don’t come with Perl, start at either CPAN Search (http://search.cpan.org) or Kobes’ Search (http://kobesearch.cpan.org/).^[22] You can browse through the categories or search directly.

Either of those resources is great since you can read the module before you download the entire package. You can also browse the distribution and have a peek at the files without the bother of installing the modules.

Before you go looking for a module, you should check whether it is already installed. One way is to just try to read the documentation with perldoc. The CGI.pm module comes with Perl (and we’ll discuss it later in this chapter), ...