title: PHP regex replace content in img src attribute?
body: <p>I'm new to PHP and have following issue. I have to sanitize images and need to replace all <code>img</code> src if it starts with <code>http://</code> with <code>/files/images/</code>.</p>
  <p>Is that possible to do with regex?</p>
  <p>I found a similar solution <a href="https://stackoverflow.com/questions/13783760/php-replace-img-tags-and-return-src">here</a> but it does't fulfil everything I need.</p>