How to make Emacs highlighting part of lines that go over 80 chars?
I use the whitespace mode:
;; `lines-tail`, highlight the part that goes beyond the
;; limit of `whitespace-line-column`
(require 'whitespace)
(setq whitespace-style '(face empty tabs lines-tail trailing))
(global-whitespace-mode t)
More: https://github.com/zma/emacs-config/blob/master/.emacs
Alternatively, you can run highlight-lines-matching-regexp with the expression .{81}. http://stackoverflow.com/questions/6344474/how-can-i-make-emacs-highlight-lines-that-go-over-80-chars