If you have PHP version 5.4 above, you may install Xdebug with a package installer as described below. If you have a PHP version lower than 5.4, you'll have to compile the Xdebug (see instruction below).
Install Xdebug with Package Installer - PHP v5.4+
1. yum update 2. yum install php-devel gcc gcc-c++ autoconf automake 3. yum install php-pear 4. pecl install Xdebug
By installing Xdebug, the xdebug.so shared object will be placed in the /usr/lib64/php/modules folder. Edit php.ini, and restart Apache. (see below).
Compile Xdebug - PHP v5.3.x or below
1. Download the Xdebug from that is compatible with your PHP version. 2. Place the xdebug-X.Y.Z.tgz in the /usr/src, and unpack with "tar xfz xdebug-X.Y.Z.tgz". 3. Change directory to "xdebug-X.Y.Z". 4. Run "phpize". This prepares the environment to compile. 5. Run "./configure". 6. Run "make". The compiled object will be placed in /usr/src/ xdebug-X.Y.Z/modules folder. The name of the shared object is xdebug.so.
Edit php.ini and restart Apache
1. Locate the php.ini file (on Centos, it is located in /etc/php.ini). 2. Add the following line under the Extensions section. zend_extension="/usr/lib64/php/modules/xdebug.so" 3. Restart apache. (i.e. service httpd restart). 4. Verify phpinfo to ensure xdebug is loaded properly.
You may also verify your Xdebug installation by calling PHP in the command-line.
% php -v PHP 5.3.3 (cli) (built: Jul 9 2015 17:39:00) Copyright (c) 1997-2010 The PHP Group Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies with Xdebug v2.2.7, Copyright (c) 2002-2015, by Derick Rethans