$user_confdir
Path to user configuration directory
Default: $HOME/.$package_name
$user_datadir
Path to user data directory
Default: $user_confdir/data
$user_logdir
Path to user log directory
Default: $user_confdir/logs
$user_tempdir
Path to user temporary directory
Default: $tmpdir/$package_name-$USER
$user_id
Numeric user id of the current user.
is_superuser()
Returns success if the current user is the superuser.
require_superuser()
Produces an error if the current user is not the superuser.