"ex" stands for extended, because it was originally an extension of the simple line editor ed. Similarly, "vi" stands for visual, because vi is the "visual" (full-screen) editing mode, which was eventually added to ex.

The commands ex and vi point to the same program, started in different modes. You can start ex by running vi -e, or you can start vi by running ex -v. Additionally, from within ex, you can start vi with the visual command (or vi for short). From inside vi, you can start ex with the command Q.

If you are familiar with vi, you can think of the ex command prompt as being the same as vi's command prompt after you type a colon (":"). For instance, the ex command "w" will write your changes to disk, just as ":w" will write changes to disk in vi.

For more in-depth information about using a line editor, see our documentation of ed, which contains extensive examples and a tutorial.

ex [ -| -s ] [ -l ] [ -L ] [ -R ] [ -r [ file ] ] [ -t tag ] [ -v ] [ -V ] 
   [ -x ] [ -wn ] [ -C ] [ +command | -c command ] file

Options

ex myfile.txt

Edits the file myfile.txt.