2. Installing Perl

Contents:
The CPAN Architecture
How Is CPAN Organized?
Installing Perl
Getting and Installing Modules
Documentation

The best things in life are free. So is Perl. Although you can get a bundled Perl distribution on CD-ROM, most people download Perl from an online archive. CPAN, the Comprehensive Perl Archive Network, is the main distribution point for all things Perl. Whether you are looking for Perl itself, for a module, or for documentation about Perl, CPAN is the place to go, at http://www.perl.com/CPAN/ . The ongoing development and enhancement of Perl is very much a cooperative effort, and CPAN is the place where the work of many individuals comes together.

2.1 The CPAN Architecture

CPAN represents the development interests of a cross-section of the Perl community. It contains Perl utilities, modules, documentation, and (of course) the Perl distribution itself. CPAN was created by Jarkko Hietaniemi and Andreas König.

The home system for CPAN is funet.fi , but CPAN is also mirrored on many other sites around the globe. This ensures that anyone with an Internet connection can have reliable access to CPAN's contents at any time. Since the structure of all CPAN sites is the same, a user searching for the current version of Perl can be sure that the latest.tar.gz file is the same on every site.

The easiest way to access CPAN is to utilize the CPAN multiplex service at www.perl.com . The multiplexor tries to connect you to a local, fast machine on a large bandwidth hub. To use the multiplexor, go to http://www.perl.com/CPAN/ ; the multiplexor will automatically route you to a site based on your domain.

If you prefer, you can choose a particular CPAN site, instead of letting the multiplexor choose one for you. To do that, go to the URL http://www.perl.com/CPAN (no trailing slash). When you omit the trailing slash, the CPAN multiplexor presents a menu of CPAN mirrors from which you select the one you want. It remembers your choice next time.

If you want to use anonymous FTP, the following machines should have the Perl source code plus a copy of the CPAN mirror list:


ftp.perl.com
 
ftp.cs.colorado.edu
 
ftp.cise.ufl.edu
 
ftp.funet.fi
 
ftp.cs.ruu.nl

The location of the top directory of the CPAN mirror differs on these machines, so look around once you get there. It's often something like /pub/perl/CPAN .

If you don't have reliable Internet access, you can also get CPAN on CD as part of O'Reilly's Perl Resource Kit . In addition to CPAN itself, the Perl Resource Kit CD includes a tool for simple installation and update of Perl modules. See http://perl.oreilly.com/ for more information.