4.6.x user.module user_access($string, $account = NULL)
4.7.x user.module user_access($string, $account = NULL)
5.x user.module user_access($string, $account = NULL)
6.x user.module user_access($string, $account = NULL, $reset = FALSE)
7.x user.module user_access($string, $account = NULL)

Determine whether the user has a given privilege.

Parameters

$string: The permission, such as "administer nodes", being checked for.

$account: (optional) The account to check, if not given use currently logged in user.

Return value

TRUE iff the current user has the requested permission.

All permission checks in Drupal should go through this function. This way, we guarantee consistent behavior, and ensure that the superuser can perform all actions.

104 calls to user_access()
aggregator_block in modules/aggregator.module
Implementation of hook_block().
aggregator_menu in modules/aggregator.module
Implementation of hook_menu().
archive_block in modules/archive.module
Implementation of hook_block().
archive_menu in modules/archive.module
Implementation of hook_menu().
block_menu in modules/block.module
Implementation of hook_menu().

... See full list

File

modules/user.module, line 325
Enables the user registration and login system.

Code

function user_access($string, $account = NULL) {
  global $user;
  static $perm = array();

  if (is_null($account)) {
    $account = $user;
  }

  // User #1 has all privileges:
  if ($account->uid == 1) {
    return 1;
  }

  // To reduce the number of SQL queries, we cache the user's permissions
  // in a static variable.
  if (!isset($perm[$account->uid])) {
    $result = db_query('SELECT DISTINCT(p.perm) FROM {role} r INNER JOIN {permission} p ON p.rid = r.rid INNER JOIN {users_roles} ur ON ur.rid = r.rid WHERE ur.uid = %d', $account->uid);

    while ($row = db_fetch_object($result)) {
      $perm[$account->uid] .= "$row->perm, ";
    }
  }

  return strpos($perm[$account->uid], "$string, ") !== FALSE;
}