Emacs 24.4 (Released 2014-10)

By Xah Lee. Date: . Last updated: .

This page is a on-going list of tips and tricks about Emacs 24.4. (released in )

If you are on linux and need to build it, see: How to Build Emacs on Linux

Editing Features

snake_case superword-mode

Move cursor by jumping over _. For example: “snake_case”

See: Emacs: Move Cursor by camelCase, snake_case


new isearch-forward-symbol-at-point. See: Emacs 24.4: Search and Highlight Words

Auto Indentation

electric-indent-mode is on by default. Now, pressing Return also does indentation. To insert line-break without indent, press Ctrl+j.

Or, turn off:

(electric-indent-mode 0) ; make return key not auto indent

indent-rigidlyCtrl+x Tab】 changed. Call it, then press {, } to adjust indentation, or press {Shift+, Shift+} to adjust indentation by tab width.

By default, the selection is the beginning of current block up to current line.

Type any other key to exit.

Delete Duplicate Lines

delete-duplicate-lines will delete duplicated lines in current text selection. The lines need not be sorted. You can try it on this:


You can use linux shell tool to do the same. [see Emacs: Run Shell]. However, shell command have problems with Unicode, and does not work well on Microsoft Windows. [see Unix Shell Util uniq Unicode Bug]

[see Emacs: List Matching Lines]


emacs 24.4 has a rectangle-mark-modeCtrl+x Space】.

Alt+x rectangle-mark-mode, then move cursor to highlight a rectangular area. Press Delete ⌦ will delete text in that rectangle area.

This feature was part of cua-mode in emacs before.

Emacs: Edit Column Text, Rectangle

Display “lambda” as λ

emacs pretty lambda 2021-09-25 g9TW
emacs pretty lambda

Emacs Init: Display Lambda as λ


New command cycle-spacing. It's like a smart just-one-space. When called repeatedly, it cycles between: one space, no space, original spacing. (this is useless)

[see Emacs: Delete Whitespace around Cursor 🚀]

Bi-direction Text Arrow Key Direction

new variable: visual-order-cursor-movement. When true (t), always moves to the left, always moves to the right, disregarding the surrounding bidirectional context.

File Features

Unique Buffer Names

emacs 24.4, by default, buffer names are unique. This is done by:

;; uniquify buffer names
(require 'uniquify) ; bundled with GNU emacs 23.2.1 or before. On in 24.4
(setq uniquify-buffer-name-style 'post-forward-angle-brackets) ; emacs 24.4 style, for example: cat.png<dirName>

Alt+x describe-variable then type uniquify-buffer-name-style to see examples of different style.

desktop-save-mode auto Save/Restore

With desktop-save-mode on, now it automatically save/restore opened files, windows config (number of windows, size, position), when quit and restart emacs.

new variable desktop-save. Default is t. When t, desktop are automatically saved when you quit.

new variable desktop-auto-save-timeout. Default value is 30 (seconds). It specifies the time interval to periodically save “desktop”. Before, it saves only when you quit emacs.

New variable desktop-restore-frames. Default value is t. When t, save and restore the frame and window configuration.

Emacs Init: Restore Opened Files (desktop-save-mode)

Web Browser: Eww

emacs eww browser keys 27289
emacs Alt+x eww browser, 2017-11-10

Bundled web browser: Emacs: Eww Web Browser

Image Viewer New Feature

Emacs: View Image File

F11 Full Screen

Alt+x toggle-frame-fullscreenF11】 to go to full screen. [see Emacs Keys: Layout Diagram]

Bookmark autosave

Bookmarks are automatically saved when emacs quit. This change may have happened before emacs 24.4. This change is not documented.

[see Emacs: Bookmark]

Menu in Text Terminals

emacs menu in text terminal
emacs menu in text terminal (emacs 24.4)

Alt+x menu-bar-openF10】 to open menu.

[see Emacs: Command to Open Menu]

Emacs Lisp Changes

New String Functions

Elisp: Trim String

Hash Table Functions

To use them, you need to first (require 'subr-x).

[see Elisp: Hash Table]


To read official list of new features, Alt+x view-emacs-news.

see also [Useful New Features in 24.4 By Artur Malabarba. At http://endlessparentheses.com/useful-new-features-in-24-4.html , accessed on 2014-10-14 ]