99-myfile.conf

# /etc/lightdm/lightdm.conf.d/99-myfile.conf
# -rwxr-xr-x 1 root root  293 Dec  4 12:49 99-myfile.conf

[Seat:*]
session-cleanup-script=/usr/local/bin/testing-logoff-script2

dir_list

root@myhost:/# ls -la / | grep test
drwxrwxrwx   2 root root     4096 Dec  4 12:58 test

testing-logoff-script2

# /usr/local/bin/testing-logoff-script2
# -rwxr-xr-x  1 root users    219 Dec  4 12:59 testing-logoff-script2

#!/bin/bash

echo "`date`: ---------------- running logoff script ----------------" >> /test/test-logoff-script.log