CODE EXAMPLE FOR SHELL

Get pid of process that created a specific window

xprop _NET_WM_PID | sed 's/_NET_WM_PID(CARDINAL) = //' # Text from the page I found the code on: Click on the window whose process should be identified. (If the desired window is not visible, use Alt+Tab to bring it to the foreground.) The above command should then output the process ID, for example: 923