How to overwrite magento controller in local directory

For Example you have to overwrite Mage/Contacts/controller/IndexController.php
Step 1: First you have to make a xml in app/etc/modules/ with name CompanyName_NameSpace.xml true local 0.1.0

Step2: You have to create the folders if not exist in local/CompanyName/NameSpace/etc/ local/CompanyName/NameSpace/controllers/ In etc folder you have to create a config.xml file Shweta_Newscontacts In controllers folder copy the Mage/Contacts/controller/IndexController.php file and include the lines: include_once('Mage/Contacts/controllers/IndexController.php'); and change the class name as: class CompanyName_NameSpace_IndexController extends Mage_Core_Controller_Front_Action Now apply changes in the file you wanted. Now also, Magento take local pool file instead of core pool.