If you can’t move the cursor on your screen or if it moves but clicking on anything is unresponsive, is there a way other than “xkill” to force stop a process when you can’t get to the command terminal? Thank you.
Sometimes it is possible to log into a text screen (if the computer is still responding to the hotkeys for that purpose),
ctrl + alt + F2
Log in with your normal user ID and password, and run commands. Often it will be possible this way to identify and kill a problematic process.
After that you can return to your desktop environment with
ctrl + alt + F7
Maybe you must turn off the whole desktop environment with
sudo service lightdm stop
and after that restart it with
sudo service lightdm start
if you are using
lightdm as I do in Lubuntu 18.04.x.
Graceful emergency shutdown
In worse cases there is
using the SysRq REISUB (reboot) or SysRq REISUO (shutdown) hotkey combination. It will often work when other things fail, and it is much better than hard shutdown with the power button.
Thank you very much. Ctl + Alt + F2 doesn’t work on my computer for whatever reason, but the Graceful ER shutdown (Alt + PrntScrn + o) worked as prescribed. Will try that next time.
Through trial and error, I discovered that Ctrl+Fn+Alt+F2 works to open the terminal, and Ctrl+Fn+Alt+F1 takes you back to the GUI. I gather this is non-standard.