index.php

<?php

$protocol = empty($_SERVER['HTTPS']) ? 'http' : 'https';
$domain   = $_SERVER['SERVER_NAME'];
$path     = $_SERVER['REQUEST_URI'];

if (strpos($domain, 'www.') === 0)
{
	// Remove the www from the domain
	$domain = substr($domain, 4);
}

header('HTTP/1.1 301 Moved Permanently');
header("Location: {$protocol}://{$domain}{$path}");