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Porcupine
Asked: 2018-09-10 11:43:42 +0800 CST

Cron not working, although the command works

  • 772

My crontab is like as follows (I am trying to change my GNOME theme)

crontab -l
0 5 * * * /usr/bin/gsettings set org.gnome.desktop.interface gtk-theme 'Adapta'
30 21 * * *  /usr/bin/gsettings set org.gnome.desktop.interface gtk-theme 'Adapta-Nokto'

Also, I created this file 

echo $USER
nikhil
cat /etc/cron.allow
nikhil

When I run the command as mentioned in crontab, both of those work.

Could you please tell if I missed out some step?

Edit:

I created a script file, which I execute with cron:

export TERM=xterm-256color
TimeHr=$(date +%H)
if ((${TimeHr}>18 || ${TimeHr}<5)); then
#if [${TimeHr} -gt 11 || ${TimeHr} -lt 5]; then
    mkdir ${HOME}/Documents/TestNight
    /usr/bin/gsettings set org.gnome.desktop.interface gtk-theme 'Adapta'
else
    mkdir ${HOME}/Documents/TestDay
    /usr/bin/gsettings set org.gnome.desktop.interface gtk-theme 'Adapta-Nokto'
fi

This is crontab

$ crontab -l
36 5,19,23 * * * bash /home/nikhil/GnomeThemeChange
@reboot bash /home/nikhil/GnomeThemeChange

cron does work as it is able to create Test Folders. But, what should I do to run gsettings inside cron?

themes cron gsettings gtk3 18.04

2 Answers

  1. Are you sure cron is not working? If you add a line like

     */1 * * * * touch /tmp/foobar123

    to your crontab, then does the file appear in /tmp?

    If that file won't appear after a minute or so, then

    ps auxw | grep cron

    or

    sudo service cron status

    If cron is not running, then try to start it with

    sudo service cron start

    But I guess the problem with your command above is, that gsettings needs to have its environment set up correctly in order to run, which it probably does not have, when run from cron.

    • 8
  2. Best Answer

    Thanks to Tomáš Pospíšek for the suggestions.

    Add the following to the script:

    PID=$(pgrep gnome-session | tail -n1)
export DBUS_SESSION_BUS_ADDRESS=$(grep -z DBUS_SESSION_BUS_ADDRESS /proc/$PID/environ|cut -d= -f2-)
    • 1