When opening 2 files in emacs, how can I have them appear side-by-side?

Question

Sometimes I launch emacs from the command line with 2 files, as follows:

emacs foo.txt bar.txt

This opens the emacs window, split vertically:

foo.txt
-------
bar.txt

How can I edit my .emacs file so that they show up side-by-side, like this?:

        |
foo.txt | bar.txt
        |

EDIT: To clarify, I know how to make this happen after emacs has launched (M-x 0, M-x 3, then re-visit bar.txt in the right window). I just want emacs to split side-by-side by default when I launch it, so I don't have to.

I just asked a very similar question and got an answer: http://stackoverflow.com/questions/6683039/opening-more-than-one-file-split-vertically-through-emacs-nw Enjoy. — yarian, Jul 17 '11 at 18:31

score 20 · Accepted Answer · answered Jul 14 '11 at 18:14

20

Here's a function that will change a pair of vertical windows to a pair of horizontal windows:

(defun 2-windows-vertical-to-horizontal ()
  (let ((buffers (mapcar 'window-buffer (window-list))))
    (when (= 2 (length buffers))
      (delete-other-windows)
      (set-window-buffer (split-window-horizontally) (cadr buffers)))))

To do this automatically on startup, add this function to emacs-startup-hook:

(add-hook 'emacs-startup-hook '2-windows-vertical-to-horizontal)

answered Jul 14 '11 at 18:14

Sean

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I originally chose one @huitseeker's answer for its simplicity, but it had one drawback. When emacs temporarily splits a window to show, for example, possible filename tab-completions, it would split the current window side-by-side. This is pretty horrible when the current window is only 80 chars long. Sean's answer splits windows side-by-side when you open multiple files on emacs launch, but otherwise lets emacs retain its usual behavior of opening temporary buffers by splitting the current window vertically. – SuperElectric Jul 26 '11 at 19:46
a small comment like `"Transform vertical split to horizontal split."` to avoid warning of a given lisp checker could be nice. – Welgriv Jun 11 '20 at 14:46

score 17 · Answer 2 · edited Jun 11 '20 at 15:33

17

The following (to add to your .emacs) makes the window splitting default result in side-by-side buffers (rather than one above the other):

(setq split-height-threshold nil) 
(setq split-width-threshold 0)

This default will also apply when you run a command such as find-file-other-window (Ctrlx4f).

(On the other hand, to manually split your window to get two side-by-side buffers, consider this answer).

edited Jun 11 '20 at 15:33

Welgriv

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answered Jul 14 '11 at 18:12

Francois G

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Six years old answer but it worked for me on Emacs 25.1.1. – Lalylulelo Jul 26 '17 at 09:06
This doesn't always work, depending on the current state of split-window-sensibly, inline documentation says ".. prefer either vertical or horizontal splitting" – dturvene Jul 30 '19 at 12:05

score 6 · Answer 3 · edited Aug 07 '17 at 04:13

6

This has worked well for me. Use the -f function-name from the command-line to have it set up your emacs split-screen workspace as you like. This gives me a 2 x 2 grid of my financial files that I update every day and sets the cursor on the appropriate window at the end. I save this to .bashrc as an alias so I can pull it up with one command (doc_financial).

alias doc_financial='emacs -nw financial_accounts.txt -f split-window-horizontally financial_budget.txt -f split-window-vertically financial_taxes.txt -f other-window -f split-window-vertically financial_tasks.txt -f other-window -f other-window -f other-window'

edited Aug 07 '17 at 04:13

Sridhar Ratnakumar

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answered Jun 29 '12 at 17:52

Jack Hamilton

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This works perfectly and should’ve been the accepted answer. Thanks! – Emily Jan 05 '14 at 20:49
Now I just need to get rid of the scratch buffer window which opens on the bottom half. – ychaouche Jun 06 '21 at 13:07

score 5 · Answer 4 · answered Jul 14 '11 at 17:37

5

Use M-x split-window-horizontally or Ctrl-x 3.

answered Jul 14 '11 at 17:37

Femi

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I know how to do it manually once emacs has launched; I just want emacs to use side-by-side splitting by default when opening multiple files. Editing question to clarify. – SuperElectric Jul 14 '11 at 18:11

score 0 · Answer 5 · edited Oct 16 '20 at 05:07

0

;; 15-Oct-20  open first file in left window
(defun my-startup-layout ()
  (let ((buffers (mapcar 'window-buffer (window-list))))
    (when (= 2 (length buffers))
      (delete-other-windows)
      (set-window-buffer (split-window-horizontally) (cadr buffers))))
)

(add-hook 'emacs-startup-hook 'my-startup-layout)
(add-hook 'emacs-startup-hook 'next-multiframe-window)
;; end of customization to open first file on left
;;

edited Oct 16 '20 at 05:07

David Buck

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answered Oct 15 '20 at 20:46

oldfwemp

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needs detail or clarity – Babak Asadzadeh Oct 19 '20 at 12:14

score -1 · Answer 6 · answered Nov 25 '15 at 14:40

-1

Ctrl -x 2 Split window, above and below

Buffer 1 (above)
Buffer 2 (Below)

Ctrl -x 3 Split window, Side by Side

Buffer 1(left) | Buffer 2 (right)

C-M-v Scroll other window

answered Nov 25 '15 at 14:40

wsha

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score -1 · Answer 7 · answered Jul 14 '11 at 17:37

-1

Use split-window-horizontally.

answered Jul 14 '11 at 17:37

Marcin

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When opening 2 files in emacs, how can I have them appear side-by-side?

7 Answers7