The Xdebug extension helps you debug your PHP scripts. It installs as a PHP extension.
Install
Install Xdebug using PECL.
pecl install xdebug
Add the following line to your PHP configuration file.
echo 'zend_extension=/usr/local/php/lib/php/extensions/no-debug-non-zts-20090626/xdebug.so' >> /usr/local/php/php.ini
Make sure the path to the extension is the same.
Restart the Web Server
The web server must be restarted for the changes to take effect.
sudo /usr/local/apache/bin/apachectl -k restart