How to know when screen is locked/unlocked in ubuntu 17.10

[inigoD]

I have try to ask this also in stackoverflow but I am not able to achieve nothing:

https://askubuntu.com/questions/974199/how-to-run-a-script-at-screen-lock-unlocks-in-ubuntu-17-10?noredirect=1#comment1562164_974199

I want to run an script on screen lock and another one on unlock... How can I know when this occurs?

I've try using dbus-monitor


#!/bin/bash

dbus-monitor --session "type='signal',interface='org.gnome.ScreenSave r'" | \
( while true
do read X
if echo $X | grep "boolean true" &> /dev/null; then
echo "locking at $(date)" >> $HOME/time_xprofile
elif echo $X | grep "boolean false" &> /dev/null; then
echo "unlocking at $(date)" >> $HOME/time_xprofile
fi
done )

But doesn't work; that signal often doesn't appear at all (neither true nor false)

And also I have try to find which process is running while screen is locked which is not running while unlocked. So I could use 'ps' command to know when it happens using this script with that procname (seems that is not 'gnome-screensaver-dialog')

#!/usr/bin/env python3
import psutil
import time
import subprocess

procname ="gnome-screensaver-dialog"
lock_command ="/path/to/lockscript"
unlock_command ="/path/to/unlockscript"

lock1 =None

while True:
--time.sleep(2)
--lock2 = procname in(p.name()for p in psutil.process_iter())
--if lock2 != lock1:
----if lock2:
------subprocess.Popen(lock_command)
------print("locked")
----else:
------subprocess.Popen(unlock_command)
------print("unlocked")
--lock1 = lock2

But I cannot find any new process while locked... the only process that I see relevant is gsd-screensaver-proxy, which is allways running...

So, I cannot find a way to do it.

How can I know when the screen flips to locked/unlocked in ubuntu 17.10 with xserver and ubuntu-gnome?

[Bryan76]

I too am trying to figure out how to run a command on screen lock and unlock. Have you made any progress?