Perl in a Nutshell, 2nd Edition

CPAN

Lets you access CPAN; search for a module, a bundle, an author, or a distribution; download a module or distribution; install it; and make it. The CPAN module can be used either interactively from the command line or programmatically:

perl -MCPAN -eshell;          # Run from the command line

or:

use CPAN;

my $obj = CPAN::Shell->install('ExtUtils::MakeMaker');

This section describes the use of the CPAN module from a program. See Chapter 2 for information on using it interactively and for details of the available commands. These commands, available interactively from the shell, are methods of the class CPAN::Shell. From a program, they are available both as methods (e.g., CPAN::Shell->install(...)) and as functions in the calling package (e.g., install(...)).

Each of the commands that produce listings of modules (r, autobundle, and u) returns a list of the IDs of all modules within the list. The IDs of all objects available within a program are strings that can be expanded to the corresponding real objects with the CPAN::Shell->expand("Module",@things) method. expand returns a list of CPAN::Module objects according to the @things arguments. In scalar context, it returns only the first element of the list.