How to Use and Setup Emacs's whitespace-mode

Xah Lee, 2009-08-14, …, 2012-09-15

This page tells you how to setup emacs's whitespace-mode (in emacs 23 or later), and how to use it.

whitespace-mode renders {spaces, tabs, newlines} characters with a visible glyph. This feature is useful for working with “tab separated values” (TSV) that's commonly used format for importing/exporting address books or spreadsheets. It's also useful in whitespace-significant languages such as Python.

To use it, call whitespace-mode. The command will toggle it on and off, for current file. Call global-whitespace-mode to toggle it globally for current emacs session.

There is also whitespace-newline-mode and global-whitespace-newline-mode. They only show newline chars.

Setting Up whitespace-mode

How to reduce colors in whitespace-mode?

;; make whitespace-mode use just basic coloring
(setq whitespace-style (quote (spaces tabs newline space-mark tab-mark newline-mark)))

How to make whitespace-mode use the pilcrow sign “¶” for newline instead of the dollar sign?

(setq whitespace-display-mappings
      ;; all numbers are Unicode codepoint in decimal. ⁖ (insert-char 182 1)
      '(
        (space-mark 32 [183] [46]) ; 32 SPACE 「 」, 183 MIDDLE DOT 「·」, 46 FULL STOP 「.」
        (newline-mark 10 [182 10]) ; 10 LINE FEED
        (tab-mark 9 [9655 9] [92 9]) ; 9 TAB, 9655 WHITE RIGHT-POINTING TRIANGLE 「▷」
        ))

How to delete trailing whitespaces?