How to run script after resume and after unlocking screen

Question

In Ubuntu 12.04 LTS, I would like to run scripts after resuming from suspend, and after unlocking my desktop. These need to run as my user, and with access to my $DISPLAY.

In particular, I would like to

• restart nm-applet to work around bug 985028
• show a custom notification using notify-send
• possibly other stuff when I get these working

When I resume, scripts in /etc/pm/sleep.d/ are run, but they run as root, without knowledge of my screen and username. It might work if I would hard code my username and export the default DISPLAY :0 in these scripts, but that feels like a very ugly hack.

Scripts in ~/.config/autostart/xyz.desktop, run after login, but they don't run after merely unlocking the screen after resume.

Is there a way to run scripts after unlocking the screen after a resume?

Answer 1

It looks like you have to hard code the username in the previous answer anyways, so here's a simple script for in /etc/pm/sleep.d if anyone is looking for a quick fix:

#! /bin/bash 
case "$1" in
    hibernate|suspend)
        sudo -u USERNAME env DISPLAY=:0 zenity --info --text "do stuff on suspend"
        exit
        ;;
    thaw|resume)
        sudo -u USERNAME env DISPLAY=:0 zenity --info --text "do stuff on resume"
        exit
        ;;
esac
exit

Answer 2

You can run a script using start-stop-daemon. start-stop-daemon can fork the thread running as different uid and gid, hence solving your problem.

What you need to do is to write a job script placed in system PATH like /usr/bin, and to create an extra daemon script in /etc/pm/sleep.d. Matching pm-suspend action like 'resume' or 'thaw' the daemon script commits the job script via 'start-stop-daemon --start $ARGs --name nm-rtvt--exec /usr/bin/job_script', where 'ARGs' could be '--chuid 1001:1001' or just '--user your_username'.

And for integrity, you might as well want the daemon script to stop the damon named 'nm-rtvt' before suspend via 'start-stop-daemon --stop <...>', matching pm-suspend action like 'suspend' or 'hibernate'.

For details, man start-stop-daemon. And there are many other examples in /etc/init.d of daemon scripts.