sudo /opt/lampp/lampp start
You can now access XAMPP from this link to see if it is well started:
http://localhost
The default folder for installing your web files and applications is /opt/lampp/htdocs. For stopping or restarting XAMPP, you can use later these commands:
sudo /opt/lampp/lampp stop
sudo /opt/lampp/lampp restart
http://www.upubuntu.com/2012/01/how-to-install-xampp-177-under-ubuntu.html