Last time, we discussed the grouping of code together into modules and packages and at the end I encouraged you to investigate your computer for software modules and also to have a go at putting your own modules together.

Today we're going to look into the ways in which our chosen languages offer other people's code modules for your delight and enjoyment. This is typically referred to as a language's package database and it is one of the many ways of getting hold of modules written by others without use of your operating system's package manager.


Perl is a very well established langauge and community. For a long time, the go-to place for Perl modules has been CPAN (The Comprehensive Perl Archive Network). Perl comes with a special module called CPAN which can be used to access the archive of modules without needing any other tooling. You can interact with it by running:

$ perl -MCPAN -eshell

Follow through the configuration, let it have a jolly good fiddle and then it'll let you search for and install perl modules on your computer.


Python's community went for a commandline tool rather than a REPL, and then being a super-special community they schismed a bit and so there's both pip and easy_install to choose from. You can install Python modules as simply as:

$ pip install <packagename>


Lua, having a much smaller and to some extent younger community around it has only managed to grow a single package manager. It is called luarocks and is closer in behaviour to pip than to CPAN.

$ luarocks install <packagename>

is all you need to get something installed for use with Lua.


Today's task is to become comfortable using the package managers of the languages of your choice. Learn how to install and remove packages, and how to search and retrieve information about different packages in the respective databases. Then think of something fun to play with, install those packages, and have a jolly good time coding with the libraries you didn't have to write yourselves.