How to run a command or script at screen lock/unlock?

I am looking for a way to store lock/unlock screen times.

A=$(date)
echo $A >> $HOME/time_xprofile

What did I try:

$HOME/.bashrc
$HOME/.bash_logout
$HOME/.bash_prompt
$HOME/.xprofile

Then I locked the screen and checked whether file appeared and it failes every time. How can I check the time than?

Solution 1:

The following script will write lock/unlock time in a file time_xprofile in your home.

#!/bin/bash

dbus-monitor --session "type='signal',interface='org.gnome.ScreenSaver'" | \
( 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 )

save the script. Give it execution permission.

chmod +x script.sh

How to run

./script.sh &

Note The script should run in back ground. Do not kill it. If you turn your screen lock/unlock while the script is running in background, your time of lock/unlock will be recorded in time_xprofile file at your home. One can use it to run some command or script at screen lock/unlock.

Mind that if you close the current terminal your script will be killed. You can use

nohup ./script.sh &

Then it will continue running even after closing the terminal.

How to kill the script

To kill the process, use in terminal

ps ax| grep "[s]cript.sh" | cut -d' ' -f2 | xargs kill

_{Above script is inspired by this answer}

Solution 2:

In ubuntu 14.04 the DBus event for screen lock unlock has changed and the new script for binding to screen lock and unlock events looks like the following

dbus-monitor --session "type='signal',interface='com.ubuntu.Upstart0_6'" | \
(
  while true; do
    read X
    if echo $X | grep "desktop-lock" &> /dev/null; then
      SCREEN_LOCKED;
    elif echo $X | grep "desktop-unlock" &> /dev/null; then
      SCREEN_UNLOCKED;
    fi
  done
)

Replace SCREEN_LOCKED and SCREEN_UNLOCKED with what you need to do.