A way to override Yii configuration settings with local settings.

index.php

<?php 
//An excerpt from Yii's index.php file

$yii_path=dirname(__FILE__).'/yii/yii.php';

//The default set of config settings
$base_config = require(dirname(__FILE__).'/protected/config/main.php');


// Optionally redefine local settings in $local_config_path.  These include:
// * your $yii_path path, relative to index.php
// * define YII_DEBUG,
// * your local database settings
//
//  $local_config_path will execute any code as well, so you can define trace level

$local_overrides = array();

//An optional 
$local_config_path = dirname(__FILE__).'/protected/config/local-main.php';

if( file_exists($local_config_path)){
    $local_overrides =  include($local_config_path);
}

//This method isn't available yet in our version of Yii - got to wait for 1.1.16. 
//Cut and pasted from 
//https://github.com/yiisoft/yii/blob/1.1.16-branch/framework/collections/CMap.php
/**
 * Merges two or more arrays into one recursively.
 * If each array has an element with the same string key value, the latter
 * will overwrite the former (different from array_merge_recursive).
 * Recursive merging will be conducted if both arrays have an element of array
 * type and are having the same key.
 * For integer-keyed elements, the elements from the latter array will
 * be appended to the former array.
 * @param array $a array to be merged to
 * @param array $b array to be merged from. You can specify additional
 * arrays via third argument, fourth argument etc.
 * @return array the merged array (the original arrays are not changed.)
 * @see mergeWith
 */
function mergeArray($a,$b)
{
    $args=func_get_args();
    $res=array_shift($args);
    while(!empty($args))
    {
        $next=array_shift($args);
        foreach($next as $k => $v)
        {
            if(is_integer($k))
                isset($res[$k]) ? $res[]=$v : $res[$k]=$v;
            elseif(is_array($v) && isset($res[$k]) && is_array($res[$k]))
                $res[$k]= mergeArray($res[$k],$v);
            else
                $res[$k]=$v;
        }
    }
    return $res;
}


//Overwrite the base values with whatever overrides were set 
$config =  mergeArray( $base_config, $local_overrides);


// if not already specified in local-main, 
// specify how many levels of call stack should be shown in each log message
defined('YII_TRACE_LEVEL') or define('YII_TRACE_LEVEL',3);


//Start the application as usual
require_once($yii_path);
include('global.php');
Yii::createWebApplication($config)->run();

protected_config_local-main-template.php

<?php
//protected/config/local-main-template.php can be checked into version cotrol
//Copy this to protected/config/local-main.php
//Ensure that .gitignore includes local-main.php your settings aren't pushed to other environments. 


// LOCAL Yii Path
//Define the Yii directory path on your machine, relative to this config file
$yii_path=dirname(__FILE__).'/../../YOUR_DIR/yii.php';

// Crank up the debug! 
defined('YII_DEBUG') or define('YII_DEBUG',true);

// specify how many levels of call stack should be shown in each log message
defined('YII_TRACE_LEVEL') or define('YII_TRACE_LEVEL',3);


// Redefine any of the properties in main.php here
// They'll be merged in index.php

return array(
	'name'=>'My Local Yii Server',
	// application components
	'components'=>array(
		'db'=>array(
			'connectionString' => 'mysql:host=YOUR_DB_HOST;dbname=YOUR_DB_NAME',
			'username' => 'YOUR_DB_LOGIN',
			'password' => 'YOUR_DB_PASSWORD',
		),
        ),
	// application-level parameters that can be accessed
	// using Yii::app()->params['paramName']
	'params'=>array(
		// this is used in contact page
		'adminEmail'=>'YOUR@EMAIL.HERE',
	),
);