Permission managment helper for Drupal

set_permissions.php

<?php

/**
 * Helper to grant/revoke permissions.
 *
 * @param
 *   A associative array map of permissions to grant/remove.
 *   Example:
 *     array(
 *       'all' => array(
 *         'use Search Autocomplete' => TRUE, // Sample for granting to all user roles.
 *       ),
 *       'role name' => array(
 *         'granting permission' => TRUE,  // Sample for granting a permission.
 *         'removing permission' => FALSE, // Sample for removing a permission.
 *       ),
 *     );
 */
function set_permissions($permission_map = array(), $severity = WATCHDOG_WARNING) {
  $all_permissions = user_permission_get_modules();
  $user_roles = user_roles();
  foreach ($user_roles as $rid => $role_name) {
    $assigning_permissions = empty($permission_map[$role_name]) ? array() : $permission_map[$role_name];
    $assigning_permissions += empty($permission_map['all']) ? array() : $permission_map['all'];
    // Clean-up non-existing permissions.
    foreach ($assigning_permissions as $permission_name => $change) {
      if (empty($all_permissions[$permission_name])) {
        watchdog('Set permission', t('Permission "%permission" does not exist and could not be %action to %role.', array(
          '%permission' => $permission_name,
          '%role' => $role_name,
          '%action' => $assigning_permissions[$permission_name] ? t('granted') : t('revoked'),
        )), NULL, $severity);

        unset($assigning_permissions[$permission_name]);
      }
    }
    user_role_change_permissions($rid, $assigning_permissions);
  }
}