Emacs markdown-mode

markdown-mode is a major mode for editing Markdown-formatted text files in GNU Emacs. markdown-mode is free software, licensed under the GNU GPL.

The latest version is markdown-mode 1.6, released on June 4. 2008:

markdown-mode is also available in the Debian emacs-goodies-el package (beginning with revision 27.0-1).

Dependencies

markdown-mode requires easymenu, a standard package since GNU Emacs 19 and XEmacs 19, which provides a uniform interface for creating menus in GNU Emacs and XEmacs.

Installation

Make sure to place markdown-mode.el somewhere in the load-path and add the following lines to your .emacs file to associate markdown-mode with .text files:

(autoload 'markdown-mode "markdown-mode.el"
   "Major mode for editing Markdown files" t)
(setq auto-mode-alist
   (cons '("\\.text" . markdown-mode) auto-mode-alist))

There is no consensus on an official file extension so change .text to .mdwn, .md, .mdt, or whatever you call your markdown files.

Usage

Although no configuration is necessary there are a few things that can be customized (M-x customize-mode).

Keybindings are grouped by prefixes based on their function. For example, commands dealing with headers begin with C-c C-t. The primary commands in each group will are described below. You can obtain a list of all keybindings by pressing C-c C-h.

Anchors: C-c C-a

C-c C-a l inserts inline links of the form [text](url). If there is an active region, text in the region is used for the link text. C-c C-a w acts similarly for wiki links of the form [[WikiLink]].
Commands: C-c C-c

C-c C-c m will run Markdown on the current buffer and preview the output in another buffer while C-c C-c p runs Markdown on the current buffer and previews the output in a browser.

C-c C-c c will check for undefined references. If there are any, a small buffer will open with a list of undefined references and the line numbers on which they appear. In Emacs 22 and greater, selecting a reference from this list and pressing RET will insert an empty reference definition at the end of the buffer. Similarly, selecting the line number will jump to the corresponding line.
Images: C-c C-i

C-c C-i i inserts an image, using the active region (if any) as the alt text.
Physical styles: C-c C-p

These commands all act on text in the active region, if any, and insert empty markup fragments otherwise. C-c C-p b makes the selected text bold, C-c C-p f formats the region as fixed-width text, and C-c C-p i is used for italic text.
Logical styles: C-c C-s

These commands all act on text in the active region, if any, and insert empty markup fragments otherwise. Logical styles include blockquote (C-c C-s b), preformatted (C-c C-s p), code (C-c C-s c), emphasis (C-c C-s e), and strong (C-c C-s s).
Headers: C-c C-t

All header commands use text in the active region, if any, as the header text. To insert an atx or hash style level-n header, press C-c C-t n where n is between 1 and 5. For a top-level setext or underline style header press C-c C-t t (mnemonic: title) and for a second-level underline-style header press C-c C-t s (mnemonic: section).
Other commands

C-c - inserts a horizontal rule.

Many of the commands described above behave differently depending on whether Transient Mark mode is enabled or not. When it makes sense, if Transient Mark mode is on and a region is active, the command applies to the text in the region (e.g., C-c C-p b makes the region bold). For users who prefer to work outside of Transient Mark mode, in Emacs 22 it can be enabled temporarily by pressing C-SPC C-SPC.

When applicable, commands that specifically act on the region even outside of Transient Mark mode have the same keybinding as the with the exception of an additional C- prefix. For example, markdown-insert-blockquote is bound to C-c C-s b and only acts on the region in Transient Mark mode while markdown-blockquote-region is bound to C-c C-s C-b and always applies to the region (when nonempty).

Markdown mode supports outline-minor-mode as well as org-mode-style visibility cycling for atx- or hash-style headers. There are two types of visibility cycling: Pressing S-TAB cycles globally between the table of contents view (headers only), outline view (top-level headers only), and the full document view. Pressing TAB while the point is at a header will cycle through levels of visibility for the subtree: completely folded, visiable children, and fully visible. Note that mixing hash and underline style headers will give undesired results.

Extensions

Besides supporting the basic Markdown syntax, markdown-mode also includes syntax highlighting for [[Wiki Links]] by default.

SmartyPants support is possible by customizing markdown-command. If you install SmartyPants.pl at, say, /usr/local/bin/smartypants, then you can set markdown-command to "markdown | smartypants". You can do this either by using M-x customize-group markdown or by placing the following in your .emacs file:

(defun markdown-custom ()
  "markdown-mode-hook"
  (setq markdown-command "markdown | smartypants"))
(add-hook 'markdown-mode-hook '(lambda() (markdown-custom)))

Experimental syntax highlighting for mathematical expressions written in LaTeX (only expressions denoted by $..$ , $$..$$, or \[..\]) can be enabled by editing markdown-mode.el and changing (defvar markdown-enable-itex nil) to (defvar markdown-enable-itex t).

Thanks

Cyril Brulebois for Debian packaging.
Conal Elliott for a font-lock regexp patch.
Edward O’Connor for a font-lock regexp fix.
Greg Bognar for menus and a patch.
Daniel Burrows for filing Debian bug #456592.
Peter S. Galbraith for maintaining emacs-goodies-el.
Dmitry Dzhus for reference checking functions.

Bugs

Markdown mode is developed and tested primarily using GNU Emacs 22 although compatibility with GNU Emacs 21 is also a priority.

Presently Markdown mode does not attempt to distinguish between multiple indentation levels and preformatted text (four or more leading spaces). I am not aware of a way to handle this using Emacs’s regexp-based font-lock facilities. Implementing a more robust approach to syntax highlighting is a high-priority item for future work.

If you find any bugs, such as syntax highlighting issues, please construct a test case and email me at jrblevin@sdf.lonestar.org. Comments and patches are welcome!

Last modified: June 4, 2008 17:04 EDT.