How to go back (ctrl+z) in vi/vim
You can use the u button to undo the last modification. (And Ctrl+R to redo it). Read more about it at: http://vim.wikia.com/wiki/Undo_and_Redo
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How do I exit the Vim editor?
Hit the Esc key to enter “Normal mode”. Then you can type : to enter “Command-line mode”. A colon (:) will appear at the bottom of the screen and you can type in one of the following commands. To execute a command, press the Enter key. :q to quit (short for :quit) :q! to quit … Read more