constants.php

/*
| Helps determine which settings to use based on the current server.
| Add this to the top of the constants.php file just under the
| opening php tag and copy it over everything down to just above
| the 'File Stream Modes' section. Modify the switches below as
| needed, and add as many switches as your setup requires.
*/

switch($_SERVER['HTTP_HOST'])
{
    case 'example1.com':
    case 'www.example1.com':
        define('SITE', 'live');
    break;
    
    case 'example1.dev':
    case 'www.example1.dev':
        define('SITE', 'expressionengine');
    break;
    
    default:
        define('SITE', 'live');
    break;
}

/*
|--------------------------------------------------------------------------
| File and Directory Modes
|--------------------------------------------------------------------------
|
| These prefs are used when checking and setting modes when working
| with the file system.  The defaults are fine on servers with proper
| security, but you may wish (or even need) to change the values in
| certain environments (Apache running a separate process for each
| user, PHP under CGI with Apache suEXEC, etc.).  Octal values should
| always be used to set the mode correctly.
|
*/

if (SITE === 'dev')
{
	define('FILE_READ_MODE', 0644);
	define('FILE_WRITE_MODE', 0666);
	define('DIR_READ_MODE', 0755);
	define('DIR_WRITE_MODE', 0777);	
}
else
{
	// This is for a live server in a suPHP environment. In a standard
	// server setup, use the settings recommended in the EE installation
	// guide.
	
	define('FILE_READ_MODE', 0644);
	define('FILE_WRITE_MODE', 0644);
	define('DIR_READ_MODE', 0755);
	define('DIR_WRITE_MODE', 0755);
}

Changed 'dev' to 'expressionengine' to make it possible to perform upgrades locally.