In Linux user has to press Ctrl +D. It depends whether you are working in one of the editors such as gedit which is basically has a GUI. However, whether the code is written in vi editor which is terminal based or any other editor all commands/programs are executed in the terminal. You have to explicitly press Ctrl +D. It is not a character. Also if you want to exit from the current process/ command you can press Ctrl +Z. You don't need to write anything. Just press it. Yeah. Still, if you haven't understood then go through the comments and take up the discussion. :).Hope it helps u. :)