gistfile1.txt

/**
 * Helper function to set permissions for node types.
 */
function pineda_set_permissions($role, $permissions, $module = 'node') {
  $rid = array_search($role, user_roles());
  foreach ($permissions as $name) {
    db_merge('role_permission')
      ->key(array(
        'rid' => $rid,
        'permission' => $name,
      ))
      ->fields(array(
        'module' => $module,
      ))
      ->execute();
  }

  // Clear the user access cache.
  drupal_static_reset('user_access');
  drupal_static_reset('user_role_permissions');
}