README for pam_shrundir

This is a "module" for PAM which manages creation of XDG_RUNTIME_DIR
as defined in the XDG Base Directory Specification [1].
The directory will be created once a user logs in the first time,
and it will be removed once she logs out last.

For it to work it must be included in /etc/pam.d -- to make it a
vivid part of session handling the file /etc/pam.d/common-session
seems best.  Include the following early:

	session optional pam_exec.so quiet /sbin/pam_shrundir

Note this PAM module does not address setting of the $XDG_RUNTIME_DIR
environment variable.  Errors will be logged via syslog.

  [1] https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html