Schedule to turn off monitor via crontab?

Question

I want to turn off monitor on a specific period of time automatically (for example between 07:00 and 11:00). Is there any command to be set in crontab file? Is there any better way?

In summary:

Turning off the monitor at 07:00 automatically.

Turning on the monitor at 11:00 automatically.

scren-saver & lock screen are disabled!

Close-voter(s): The answer here is generally applicable to other people who want something similar--even if the OP never replied back this should still not be closed as not reproducible. (Also, the OP said it would take about *one day* to come back and check if the answer worked.) If there's some other reason to close this, I recommend commenting. — Eliah Kagan, Sep 06 '13 at 03:09
Related [Manually turn off monitor](https://askubuntu.com/questions/253818/manually-turn-off-monitor/253821#253821) — Zanna, Aug 24 '17 at 19:41

score 4 · Answer 1 · edited Nov 21 '13 at 21:37

Assuming that you are using the default gnome-screensaver for Ubuntu, open a terminal and run next commands followed by instructions:

mkdir -p bin - this command will make a bin directory in your home folder if you don't already have it.
gedit ~/bin/screen_on_or_off.sh - this will create the new file screen_on_or_off.sh in gedit.

Copy and paste the next script:

#!/bin/bash

export DISPLAY=:0 #very important if you want to be runned by a cron job

current_hour=$(date +"%k")

# Defining the disable_screensaver function
function disable_screensaver {
    # Disabling sleep time
    # 0 value will never turn the screen off; you can change this value as you wish:
    # for example to turn the screen of after 10 min, use 600
    gsettings set org.gnome.settings-daemon.plugins.power sleep-display-ac 0
    gsettings set org.gnome.settings-daemon.plugins.power sleep-display-battery 0
    gsettings set org.gnome.desktop.session idle-delay 0
}

# Defining the enable_screensaver function
function enable_screensaver {
    # Enabling sleep time to 1 second
    gsettings set org.gnome.settings-daemon.plugins.power sleep-display-ac 1
    gsettings set org.gnome.settings-daemon.plugins.power sleep-display-battery 1
    gsettings set org.gnome.desktop.session idle-delay 1

    notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo error)" "Let's go to sleep now!"
}

if [ "$current_hour" -ge "7" ] && [ "$current_hour" -lt "11" ]; then
    enable_screensaver
else
    disable_screensaver
fi

exit 0

Save the file and close it.
Go back into terminal and run: chmod +x screen_on_or_off.sh - to grant execute access for the script.
Just for test, to run your new script, type in terminal ~/bin/screen_on_or_off.sh.
Edit the crontab entries using crontab -e command (by default this will edit the current logged-in users crontab) and add the following line:
```
*/1 * * * * /home/$USER/bin/screen_on_or_off.sh  #change $USER with your username
```
I have set the cron job for every minute, but you can change as you wish or as you think is better. See http://en.wikipedia.org/wiki/Cron in this sense.
Save the file and check the new crontab entry with crontab -l.

Now your screen will turn off every day between 7 and 11.

I've disabled gnome-screensaver and lock-screen, this is the reason that I want to turn off the monitor by command line automatically! Another note: The computer is at work, I'm on vacation now; however, I'll check your instruction tomorrow and put a feedback here :) — mini, Jun 30 '13 at 17:54

score 3 · Answer 2 · answered Jul 20 '21 at 17:27

3

Newer and much simpler answer, put this in cron:

0 07 * * *  export DISPLAY=:0 && xset dpms force off
0 11 * * *  export DISPLAY=:0 && xset dpms force on

answered Jul 20 '21 at 17:27

Daniel Segel

31
1

Schedule to turn off monitor via crontab?

2 Answers2

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