If the ``$VISUAL`` environment variable is set, it will be used as the program to edit the function. If ``$VISUAL`` is unset but ``$EDITOR`` is set, that will be used. Otherwise, a built-in editor will be used. Note that to enter a literal newline using the built-in editor you should press :kbd:`Alt`\ +\ :kbd:`Enter`. Pressing :kbd:`Enter` signals that you are done editing the function. This does not apply to an external editor like emacs or vim.
-``-e command`` or ``--editor command`` Open the function body inside the text editor given by the command (for example, ``-e vi``). The special command ``fish`` will use the built-in editor (same as specifying ``-i``).
This will open up your editor, allowing you to modify the function. When you're done, save and quit. Fish will reload the function, so you should see the changes right away.