title: regex with multiline modifier work on server but not work on xampp localhost
body: <p>I have a regex that work fine on internet and <a href="https://regex101.com/r/oL8iA9/1" rel="nofollow">Regex101</a></p>
  
  <p>I use below PHP codes to test it in localhost </p>
  
  <pre><code>&lt;?php
  $regex = "/(?:دفتر)(?:.*?)\:(?:.*?|\n)(^(?!.*\@).+)/mu";
  preg_match_all($regex,$str, $arr);
  print_r($arr);
  ?&gt;
  </code></pre>
  
  <p>but when run it on XAMPP localhost it return's empty array , what's wrong with this code and, how can I fix it </p>