9.1 The vi Editor
9.1.5 Saving files and quitting vi (last-line mode)
Several last-line mode commands are available for saving your work and exiting vi. You should save your work to disk periodically using the :w (write) command. This writes the file to disk and leaves you in vi. To save a copy of the file currently being edited to disk under a new name, use the :w command followed by a new file name. This is a good way to make a backup of the file. To save the file and quit, you can use either the :wq or ZZ commands. If you have accidentally made changes and want to discard them without saving or you want to exit vi and ensure that you have not made any changes, use the :q! (quit) command. If you open a read-only file and wish to modify it, you can save changes and overwrite the existing file with the :wq! (write-quit) command. The Figure shows the various save/exit options.