php 도메인 추출 정규식

원본/출처:
http://setint.tistory.com/entry/php-%EB%8F%84%EB%A9%94%EC%9D%B8-%EC%B6%94%EC%B6%9C-%EC%A0%95%EA%B7%9C%EC%8B%9D

if ( ! function_exists('getDomainName'))
{
	function getDomainName($url)
	{
		$value = strtolower(trim($url));
		$url_patten = '/^(?:(?:[a-z]+):\/\/)?((?:[a-z\d\-]{2,}\.)+[a-z]{2,})(?::\d{1,5})?(?:\/[^\?]*)?(?:\?.+)?$/i';
		$domain_patten = '/([a-z\d\-]+(?:\.(?:asia|info|name|mobi|com|net|org|biz|tel|xxx|kr|co|so|me|eu|cc|or|pe|ne|re|tv|jp|tw)){1,2})(?::\d{1,5})?(?:\/[^\?]*)?(?:\?.+)?$/i';

		if (preg_match($url_patten, $value))
		{
			preg_match($domain_patten, $value, $matches);
			$host = (!$matches[1]) ? $value : $matches[1];
		}
		return $host;
	}
}