Protocol-Regex-Maker.php

<?php

$allowed = array("https", "http");

function protocolRegex($array){
	if(empty($array)) { return "(\/\/)"; }
	
	foreach($array as $i => $v){
		if(empty($v)){
			unset($array[$i]);
		}
	}
	$array = implode("|", $array);
	return "((".$array."):|\/\/)";
}

echo protocolRegex($allowed);

?>