PHP BLA LOOK - Web Based Text Matching

Find occurrences of BLA followed by LOOK in a web based text using PHP regular expressions.

<?php
$re = '/BLA(?:(?!BLA).)*?LOOK/';
$str = 'BLA text text text  text text text BLA text text text text LOOK text text text BLA text text BLA';

preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);

var_dump($matches);