module_invoke_last()

gistfile1.php

function module_invoke_last($hook) {
  $args = func_get_args();
  // Remove $hook from the arguments.
  unset($args[0]);
  $result = null;
  foreach (module_implements($hook) as $module) {
    $function = $module . '_' . $hook;
    if (function_exists($function)) {
      $result = call_user_func_array($function, $args);
    }
  }
  return $result;
}