Another way is to delete whitespace only in some modes. Example from my .emacs (setq-default show-trailing-whitespace t) (defun delete-trailing-whitespace-

Another way is to delete whitespace only in some modes. Example from my .emacs (setq-default show-trailing-whitespace t) (defun delete-trailing-whitespace-hook() (add-hook 'before-save-hook 'delete-trailing-whitespace)) (add-hook 'ruby-mode-hook 'delete-trailing-whitespace-hook) (add-hook 'python-mode-hook 'delete-trailing-whitespace-hook) (add-hook 'lisp-mode-hook 'delete-trailing-whitespace-hook)