pam_rundir is a PAM module that can be used to provide user runtime directory, as described in the XDG Base Directory Specification.
The directory will be created on login (open session) and removed on logout
(close session), and its full path made available in an environment variable,
usually $XDG_RUNTIME_DIR.
pam_rundir - Copyright (C) 2015 Olivier Brunel jjk@jjacky.com
pam_rundir is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version.
pam_rundir is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with pam_rundir (COPYING). If not, see http://www.gnu.org/licenses/
Some useful links if you're looking for more info:
Plus, pam_rundir comes with man pages.