In this article, we will guide you through the process of fixing the “xset: unable to open display” error and how to blank your screen on Ubuntu. This error typically occurs when you try to modify the power management settings on your display.
To fix the "xset: unable to open display" error on Ubuntu, you need to set the DISPLAY environment variable correctly using the export command. Once the variable is set, you can use the xset command to blank your screen by running "xset dpms force off". If you encounter further issues, you can try using the vbetool utility as an alternative.
Understanding the Error
Before we delve into the solutions, let’s understand what the error message “xset: unable to open display” means. The xset command is a utility for setting user preferences in X, the window system used by Ubuntu and other Unix-like operating systems. The error message “unable to open display” means that xset cannot communicate with the X server (the software that manages your display), usually because the DISPLAY environment variable is not set correctly.
Setting the DISPLAY Variable
The DISPLAY Variable
The DISPLAY environment variable in Unix and Linux specifies which display server xset should connect to. It is usually set to :0, which means the first display server on the local machine.
How to Set the DISPLAY Variable
To set the DISPLAY variable, you can use the export command in the terminal:
export DISPLAY=:0This command sets the DISPLAY variable to :0 for the duration of the current session. You can check the current value of the DISPLAY variable with the echo command:
echo $DISPLAYIf you see :0 or similar as the output, it means the DISPLAY variable is set correctly.
Using xset to Blank the Screen
Once the DISPLAY variable is set correctly, you should be able to use xset to blank the screen. Here’s how:
xset dpms force offIn this command, dpms stands for Display Power Management Signaling, a standard for power saving in monitors. force off tells xset to immediately put the display into power off mode.
Using vbetool as an Alternative
If you’re still having trouble with xset, you can try vbetool, another utility that can manipulate the power state of your display. To install vbetool, use the following command:
sudo apt install vbetoolOnce installed, you can use vbetool to turn off the display:
sudo vbetool dpms offIn this command, dpms off does the same thing as in the xset command: it puts the display into power off mode.
Conclusion
In this article, we’ve discussed how to fix the “xset: unable to open display” error and blank your screen on Ubuntu. We’ve covered how to set the DISPLAY environment variable, how to use xset to blank the screen, and how to use vbetool as an alternative. We hope this guide has been helpful. If you have any further questions, feel free to ask in the comments below.
The error message "xset: unable to open display" means that the xset command is unable to communicate with the X server, usually because the DISPLAY environment variable is not set correctly.
To set the DISPLAY variable, you can use the export command in the terminal. For example, you can run export DISPLAY=:0 to set the DISPLAY variable to :0 for the current session.
You can use the echo command followed by $DISPLAY to check the current value of the DISPLAY variable. For example, running echo $DISPLAY will display the current value.
Once the DISPLAY variable is set correctly, you can use the command xset dpms force off to blank the screen. This command puts the display into power off mode.
An alternative to xset is vbetool. You can install vbetool using the command sudo apt install vbetool. Once installed, you can use vbetool dpms off to turn off the display.
