IntelliJ IDEA terminal exiting process command (control + c) doesn't work

According to your settings it should be Meta + C. Normally it is the same key combination used to 'copy' purpose.

Anyway you can check and use as follows,

• Go to Settings -> Keymap

• On the top-right corner type 'copy' and press Enter.
• The first key pair (here Meta + C ) should be the one you needed.

You can also change the keymap you are using from the 'keymap' drop down menu appearing here, and switch to a different one, if you are not comfortable with your settings. 'Mac OS X 10.5 + would be a good one for you.

You can close the terminal session by clicking the red X on the left of the the terminal tool window, and this should also kill any processes created by the terminal. If you want to run another command, just open the terminal back up.

Control+C and then ENTER works in 2018.3 (in Windows).