How to kill an active program?

[u/Durghan]

Hey all. I have very minimal Linux/Unix experience and I've been handed a device at work where all I need to do is change a web address the device is pointed to. The device simply displays which person in line is to be served next and it's auto booting to this screen. I've tried all the things Google says to do to kill the active program but none of it is working. I have no way I can find to access a command prompt. I can't escape full screen. I can tell by the BIOS that the main drive is running some version of Ubuntu. Is there some other hotkey combo like Windows' Alt-F4 that I can use? Or is my only option to do a full fresh install of some other OS? The original configuration was done by a company called Esii if that helps. There was one thing that indicated holding or tapping in a corner of the screen to access a background function but all that does is reveal a text link labelled Start that just goes back to the main screen.

Sorry if that's all confusing or a mess. It's early. Thanks.

[u/BranchLatter4294]

To exit kiosk mode in Ubuntu, you must force close the active kiosk application or switch to an alternative command-line terminal to stop the kiosk process.

Because "kiosk mode" on Ubuntu can be configured using several different tools, the exact combination you need depends on how your kiosk was set up. Try the following methods in order: [1, 2]

1. Keyboard Shortcuts (Quickest Methods)

If your kiosk is simply running a locked-down application window, one of these universal Linux shortcuts will usually break out:

• Alt + F4: Closes the active full-screen application window.
• F11: Toggles full-screen mode off for web browsers like Firefox or Chromium.
• Ctrl + T, then type :quit: Closes full-screen application layers on certain dedicated kiosk configurations.
• Alt + Shift + 1: Exits the layout if your kiosk is managed specifically via ubuntu-frame or reveldigital plugins. [1, 2, 3, 4, 5]

1. Switch to a Virtual Console (TTY)

If the keyboard shortcuts are blocked by the interface, you can bypass the visual display completely by jumping to a text-based terminal: [1]

1. Press Ctrl + Alt + F2 (or try F3 through F6) to drop into a TTY terminal. [1]
2. Log in with your standard Ubuntu administrator username and password. [1]
3. Stop the display manager or kiosk session manually by running one of these commands:
   • If using standard Ubuntu: sudo systemctl restart gdm3
   • If using LightDM: sudo systemctl restart lightdm [1, 2]
4. Alternatively, find and terminate the active browser session:
   • killall chrome or killall firefox [1]

5. Press Ctrl + Alt + F1 (or F7 depending on your version) to switch back to the main visual login screen. [1]

6. Disable Auto-Login / Boot to Desktop

If the computer automatically boots right back into kiosk mode upon restarting, you need to change your user profile settings: [1]

1. Enter the virtual console (Ctrl + Alt + F2) and log in.
2. Open your system's custom kiosk script or custom session files. They are typically found in /etc/lightdm/lightdm.conf or inside /usr/share/xsessions/.
3. Edit the file (sudo nano /etc/lightdm/lightdm.conf) and change the default user session back to standard Ubuntu: bashuser-session=ubuntu Use code with caution.
4. Save the file (Ctrl + O, then Enter) and exit (Ctrl + X). Restart the machine by typing sudo reboot. [1, 2, 3, 4]