How do you update a file in Unix?

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2Use the arrow keys to move the cursor to the part of the file you want to change. 3Use the i command to enter Insert mode. 4Use the Delete key and the letters on the keyboard to make the correction. 5Press the Esc key to get back to Normal mode.

How do you update a file in Terminal?

If you want to edit a file using terminal, press i to go into insert mode. Edit your file and press ESC and then :w to save changes and :q to quit.