Learning Perl, Fourth Edition

How Can I Get Perl?

You probably already have it. At least, we find Perl wherever we go. It ships with many systems, and system administrators often install it on every machine at their site. If you can’t find it on your system, you can get it free.

Perl is distributed under two different licenses. For most people who use Perl, either license is adequate. If you’ll be modifying Perl, however, you’ll want to read the licenses more closely because of the small restrictions on distributing the modified code. For people who won’t modify Perl, the licenses say, “It’s free—have fun with it.”

So, it’s free and runs rather nicely on nearly everything that calls itself Unix and has a C compiler. You download it, type a command or two, and it starts configuring and building itself. Better yet, get your system administrator to type those two commands and install it for you.^[18] Besides Unix and Unix-like systems, people have become addicted enough to Perl to port it to other systems, like the Macintosh,^[19] VMS, OS/2, MS/DOS, every modern species of Windows, and probably more by the time you read this.^[20] Many of these ports of Perl come with an installation program that’s easier to use than the process for installing Perl on Unix. Check for links in the “ports” section on CPAN.

What Is CPAN?

CPAN is the Comprehensive Perl Archive Network, your one-stop shopping for Perl. It has the source code for Perl itself, ready-to-install ports of Perl to all sorts of non-Unix systems,^[21] examples, documentation, ...