How to execute a script on logut in Ubuntu 14.04

**squirrel2003** · March 7th, 2015

http://askubuntu.com/questions/29331...down-in-ubuntu

In this thread it gets explained where to put a script so it executes everytime one logs out of ubuntu.

The file /etc/lightdm/lightdm.conf is missing in my installation of Ubuntu 14.04.

Where is i gone?
Wehere can i paste the line session-cleanup-script=/path/to/script to execute the script i created on logout.

Thanks if you helping.

**ian-weisser** · March 7th, 2015

What kinds of cleanup do you envision?

Do-an-action-upon-logout may be unreliable, because some sessions end without a logout.
Power failures, hardware failures, and several kinds of crashes may end a session. Sometimes merely resetting the X server, other times causing real grief.

One answer:
In 14.04, systemd-logind (provided by the libsystemd-login0 package) emits a dbus signal when a session logs in or out.
You can easily write a listener for those signals. It may need a little logic to read the signal and determine if it should launch the script.

**CantankRus** · March 7th, 2015

Not sure if this still works but from my notes.... "In 14.04 add to /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf"

Code:

gksudo gedit /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf

You will probably need to restart to reload lightdm, then your session-cleanup-script should work on next logout.

**squirrel2003** · March 7th, 2015

Originally Posted by ian-weisser

What kinds of cleanup do you envision?

Do-an-action-upon-logout may be unreliable, because some sessions end without a logout.
Power failures, hardware failures, and several kinds of crashes may end a session. Sometimes merely resetting the X server, other times causing real grief.

One answer:
In 14.04, systemd-logind (provided by the libsystemd-login0 package) emits a dbus signal when a session logs in or out.
You can easily write a listener for those signals. It may need a little logic to read the signal and determine if it should launch the script.

What i want to achieve is that a script running

Code:

sdmem -llfv

will execute upon logout.
The idea behind it is to install ubuntu to a thumbdrive withan encrypted home partition. Before i leave the house i shut down my netbook, plugin the usb drive, start the system, login, start recording using cheese or motion, logout and leave the house.
This should in my theory prevent an intruder to perform a cold boot attack in order to extract the login password, or the home directory encryption key and perform any changes on my hardware before leaving the appartment and make it look for me as if nothing has happened.
I have read about some special cases in which sdmem would not be able to fully wipe the RAM and one person told me i should try out TRESOR but first i want to finish with this task.

Originally Posted by CantankRus

Not sure if this still works but from my notes.... "In 14.04 add to /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf"

Code:

gksudo gedit /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf

You will probably need to restart to reload lightdm, then your session-cleanup-script should work on next logout.

Thank you i will try it the way you described.

**squirrel2003** · March 7th, 2015

I have edited the 50-unity-greeter.conf adding the line:
session-cleanup-script=/home/ubunt/Dokumente/Scripts/sdmem.sh in the end of the file.
Then i saved the file and rebooted.
After entering my login credentials i was presented with a black screen.
I restored my Laptop and am wondering if i misunderstood something and made a mistake editing the greeter.conf file or what else might cause the failure.
One of the first things i did on this laptop was applying the brightness fix as described in the following link.
http://itsfoss.com/fix-brightness-ubuntu-1310/
Could this change cause a problem?

**squirrel2003** · March 9th, 2015

Anyone?

**CantankRus** · March 9th, 2015

Test something simple to run when you logout.
eg I just use this to clear recent in nautilus
lightdm-session-cleanup.sh

Code:

#!/bin/bash

## Clears Recent in nautilus
echo > /home/glen/.local/share/recently-used.xbel

Edit for your username

and my /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf file...

Code:

[SeatDefaults]
greeter-session=unity-greeter
session-cleanup-script=/home/glen/scripts/lightdm-session-cleanup.sh

Edit for path to script
Check recent in nautilus before and after you logout.

If recent files are cleared, problem is in your original script.
Post the script your using.