0

I'm trying to use a cron job to see when the battery gets lower than a given threshold, and then to send a battery critical notification. However, when I make the cron job execute a script every minute, and make the script send me a notification, it doesn't work.

To make sure that it's not a permissions issue with the script or something causing the cron job to not run, I made the script create a file instead, and it worked. This is the crontab entry:

* * * * * /home/aravk/test.sh

And, to simplify the problem, these are the contents of test.sh:

#!/bin/sh
/usr/bin/dunstify hi

No notification shows up, however. The script does work when I execute it manually. I also tried setting the DISPLAY environment variable to :0 by changing the crontab entry to * * * * * export DISPLAY=:0 && /home/aravk/test.sh, but it still didn't work. How do I send notifications from a script executed by a cron job? I'm on Arch Linux, if it's relevant.

Improve this question
2
  • What's output of running /usr/bin/dunstify hi? Make sure libnotify is installed.
    – Tuyen Pham
    Jan 7, 2020 at 6:25
  • @TuyenPham it shows a notification saying hi. Like I said in the question, the script does work when I execute it manually.
    – aravk33
    Jan 7, 2020 at 12:06

3 Answers 3

Reset to default
6

I added this to my crontab and all my notifications work (currently tested with zenity and notify-send):

DISPLAY=":0.0"
XAUTHORITY="/home/me/.Xauthority"
XDG_RUNTIME_DIR="/run/user/1000"
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
Improve this answer
2
  • 1
    Holy shit, that worked!! Only the XDG_RUNTIME_DIR variable seems to be necessary for notifications, though
    – aravk33
    Jan 7, 2020 at 12:53
  • I kept it the same as root's crontab , where it was necessary.
    – ajgringo619
    Jan 7, 2020 at 15:53
0

You have to get the crontab job access to some environment variables.. I just solved this probleme in my Kali Linux, so open terminal and type export hit enter and a message with info of the variables will show up..

get to the line where declare -x DISPLAY=":1" exists (value may be 0 not 1) just copy the DISPLAY=":1" and past it in your crontab line, then go to the line where declare -x XAUTHORITY="/run/user/1000/gdm/Xauthority" exists and copy this part XAUTHORITY="/run/user/1000/gdm/Xauthority", then past that one too in your crontab line..

your crontab would be like:

* * * * * DISPLAY=':1' XAUTHORITY='/run/user/1000/gdm/Xauthority' your_command

Improve this answer
0

In my case, the issue was with using root user with notify-send. I realized this when I saw that sudo notify-send didn't work on the terminal but just notify-send (i.e. with current user) did. So instead of editing the usual /etc/crontab which is used by root, I had a custom cron script created for myusername. Please check my whole answer here.

Improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .