Check out the PEAR Manual: http://pear.php.net/manual/en/ [1].
Install PEAR: http://pear.php.net/manual/en/guide.users.commandline.cli.php [2].
$ pear help install
Show Config: http://pear.php.net/manual/en/guide.users.commandline.config.php [3].
$ pear config-show
Installing Packages: http://pear.php.net/manual/en/guide.users.commandline.installing.php [4].
/* the gist of it */ $ pear install foo Ignoring installed package pear/foo Nothing to install
Getting information about packages: http://pear.php.net/manual/en/guide.users.commandline.packageinfo.php [5].
http://pear.php.net/manual/en/packages.php [6]
Links:
[1] http://pear.php.net/manual/en/
[2] http://pear.php.net/manual/en/guide.users.commandline.cli.php
[3] http://pear.php.net/manual/en/guide.users.commandline.config.php
[4] http://pear.php.net/manual/en/guide.users.commandline.installing.php
[5] http://pear.php.net/manual/en/guide.users.commandline.packageinfo.php
[6] http://pear.php.net/manual/en/packages.php