Trailing Whitespace

There are different ways to handle trailing whitespace in Emacs

Visualize trailing whitespace

Just set the show-trailing-whitespace variable:

(setq show-trailing-whitespace t)

Delete trailing whitespace

You can delete trailing whitespace in the entire buffer using M-x delete-trailing-whitespace.

To automate trailing whitespace deletion before saving the buffer in certain modes, you can add local hooks, e.g:

(add-hook 'c-mode-hook (lambda () (add-to-list 'write-file-functions 'delete-trailing-whitespace)))

See also

• Whitespace-mode