This script automates the process of changing the GNOME Display Manager background of Ubuntu version 20.04 Focal Fossa.
This script wont work with any older version of Ubuntu because they have a different way of dealing with gdm settings.
This tool was made specifically to work with Ubuntu 20.04 as it now bundles all configuration files inside the gdm3-theme.gresource file.
Please, note that GDM3 WON'T ACCEPT FILES NAMES WITH SPACES, so don't use them to set your background
bacause you may end up with a weird gdm screen. Of course, you can go back to your original gdm
theme with the --restore option.
First, you will need to install libglib2.0-dev-bin with sudo apt install libglib2.0-dev-bin
Then, you can download the script with the command below:
curl -L -O github.com/thiggy01/ubuntu-20.04-change-gdm-background/raw/master/ubuntu-20.04-change-gdm-background
And give it execution permition with chmod +x gdm-change-login-background
Run the script with root privileges such as sudo ./ubuntu-20.04-change-gdm-background /path/to/image.
If you see a message login image sucessfully changed, then, when you restart gdm or reboot your
computer, your gdm background should be covered with the image you selected.
You can restore your original gdm theme any time with sudo ./ubuntu-20.04-change-gdm-background --restore.
If you feel this tool was useful and want to show some appreciation, you can donate me via https://ko-fi.com/thiggy01.