Fetching custom Authorization header from incoming PHP request

For token based auth:

  $token = null;
  $headers = apache_request_headers();
  if(isset($headers['Authorization'])){
    $matches = array();
    preg_match('/Token token="(.*)"https://stackoverflow.com/", $headers['Authorization'], $matches);
    if(isset($matches[1])){
      $token = $matches[1];
    }
  }