Fungsi mengambil gambar pertama dari posting

<?php
function get_image(){
  $first_img = '';
  ob_start();
  ob_end_clean();
  $output = preg_match_all('/<img.+src=[\'"]([^\'"]+)[\'"].*>/i', $post, $matches);
  $first_img = $matches [1] [0];
  return $first_img;
?>