sudo apt-get install php-pear
sudo apt-get install php5-dev
sudo pecl install dbase
sudo vi etc/php5/mods-available/dbase.ini < extension=dbase.so
sudo php5enmod dbase
sudo service apache2 restart
That should do it. I would do that on a temp Ubuntu and just copy the dbase.so to the prod, so you do not install all that dev stuff in your prod env.