Emacs in -nw mode colors source code files, in this screenshot you see how emacs colors the .rb file I opened. Over the weeks/months I've gotten used to the coloring.

Despite how hard I try, there always comes a time when I'm not in emacs, and I'm doing a cat in the Terminal.app bash shell. So much like you can pipe a compact block of json to get nicely indented json, is it possible to pipe a .rb file to some scripts that runs Emacs and extracts the syntax coloring that Emacs uses?

enter image description here

  • 2
    Please clarify how this is relevant to Emacs. I guess what you're really asking is "how to use Emacs in a pipe to color my file". If so, please says it.
    – Stefan
    May 8, 2019 at 1:57
  • 3
    Yes, translate Emacs font-lock faces into ANSI escape code, see github.com/Lindydancer/e2ansi
    – xuchunyang
    May 8, 2019 at 8:04
  • You can install/use the package highlight from homebrew - see discussion on this page: unix.stackexchange.com/questions/267361/… - this package support colour customisation.
    – Ian
    May 8, 2019 at 12:47
  • I really don't understand why this question is put on hold -- I've voted for it to be reopened. Anyway, I asked myself the same thing a couple of years ago -- when I didn't find any package I wrote my own (github.com/Lindydancer/e2ansi as @ xuchunyang already posted). Any text Emacs can highlight, it can render using ANSI sequences so it can be viewed in a terminal, using the command e2ansi-cat. It integrates with pagers like moreand less so anything you view with them becomes highlighted automatically. May 9, 2019 at 19:24
  • really don't understand why this question is closed May 15, 2019 at 21:49

1 Answer 1


You can use the syntax coloring outside Emacs, two working examples are htmlize for the web and e2ansi for the terminal. For your need, you can use e2ansi-cat provided by e2ansi, here is a screenshot of it:

screenshot of cat and e2ansi-cat

By the way, if you use Eshell, you can easily get the syntax coloring:

(defun eshell/cat-with-syntax-highlight (filename)
  (let ((existing-buffer (get-file-buffer filename))
        (buffer (find-file-noselect filename)))
     (with-current-buffer buffer
    (unless existing-buffer
      (kill-buffer buffer))

screenshot of cat-with-syntax-highlight

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