Emacs: Split Windows

Emacs Split Window Commands

Purpose	Command Name	Key
split top/bottom	split-window-below	【Ctrl+x 2】
split left/right	split-window-right	【Ctrl+x 3】
unsplit all	delete-other-windows	【Ctrl+x 1】
remove current pane	delete-window	【Ctrl+x 0】
move cursor to next pane	other-window	【Ctrl+x o】

Note, emacs terminology of window/frame is reversed from modern meaning.

• emacs jargon “window” means frame or pane.
• emacs jargon “frame” means window.

Easy Keys for Split Window

Split/unsplit window panes are some of the most frequently used commands, because emacs often generates output in a splits window. [see Emacs's Command Frequency Statistics]

I recommend setting easy keys for them.

Put the following in your emacs init file.

;; easy keys for split windows
(global-set-key (kbd "M-3") 'delete-other-windows) ; 【Alt+3】 unsplit all
(global-set-key (kbd "M-4") 'split-window-below)
(global-set-key (kbd "M-$") 'split-window-right)
(global-set-key (kbd "M-RET") 'other-window) ; 【Alt+Return】 move cursor to next pane
(global-set-key (kbd "M-0") 'delete-window)  ; remove current pane

[see Emacs: How to Define Keys]

Note: I do not recommend keys like 【Alt+1】 or 【Ctrl+1】 , because that got me Repetitive Strain Injury. [see Programer Hand Health: vi Esc Key Syndrome]

Adjust Split Pane Size

You can adjust the split pane size by mouse dragging the mode line (status bar). For windows split left/right, drag the split position on the horizontal mode line.

Or, you can use keys. Here's the commands:

Emacs Pane Size Adjustment Commands

Command	Key	Purpose
enlarge-window	【Ctrl+x ^】	increase height
shrink-window	◇	decrease height
enlarge-window-horizontally	【Ctrl+x }】	increase width
shrink-window-horizontally	【Ctrl+x {】	decrease width
shrink-window-if-larger-than-buffer	【Ctrl+x -】	shrink a window to fit its content.
balance-windows	【Ctrl+x +】	make all panes same width/height

Most of these commands also take a argument. Alt+x universal-argument 【Ctrl+u】 first then type a number, then, call the command that adjust window size.

If you use these commands often, you probably want to give them a easy key such as F8, so you can hold it to enlarge/shrink window size. [see Emacs: How to Define Keys]