PHPUnit is the de-facto standard for unit testing in PHP projects. It provides both a framework that makes the writing of tests easy as well as the functionality to easily run the tests and analyse their results.
PHPUnit should be installed using the PEAR Installer. This installer is the backbone of PEAR, which provides a distribution system for PHP packages, and is shipped with every release of PHP since version 4.3.0.
The PEAR channel (pear.phpunit.de) that is used to distribute PHPUnit needs to be registered with the local PEAR environment. Furthermore, components that PHPUnit depends upon are hosted on additional PEAR channels.
pear channel-discover pear.phpunit.de
pear channel-discover components.ez.no
pear channel-discover pear.symfony-project.com
This has to be done only once. Now the PEAR Installer can be used to install packages from the PHPUnit channel:
pear install phpunit/PHPUnit
After the installation you can find the PHPUnit source files inside your local PEAR directory; the path is usually /usr/lib/php/PHPUnit.
The documentation for PHPUnit is available in different formats: