In my Ubuntu 16.04 , 64 bit OS, I tried the following
* * * * * export DISPLAY=:0.0 && notify-send Hey "How are you"
And
* * * * * export DISPLAY=:0.0 && /usr/bin/notify-send Hey "How are you"
But, unfortunately, it is not working.
I found in other threads that the above command works.
How to run it on my machine?
The command notify-send Hey "How are you" works on the terminal.
Also the command * * * * * echo "trying to notify at $(date)" >> /home/user/Desktop/test.txt works fine from crontab file
The output of $ echo $DISPLAY is :0
also
$ who -u
cosmicraga tty7 2016-11-07 06:45 06:12 2524 (:0)
cosmicraga pts/1 2016-11-07 12:54 . 6333 (:0)
cosmicraga pts/17 2016-11-07 12:50 00:02 6333 (:0)