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I am very very new to emacs. I want something like this. Every time I open a new buffer, it should split current winodow vertically. How should I change .emacs file. Please provide some pointers.

username_4567
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    What do you mean? When Emacs opens, it has a specific buffer opened up, vertically split? Or when you open a specific buffer, it splits vertically? Or something else. – zck Nov 23 '13 at 20:46
  • @Robin Green is correct. I like the `emacs-startup-hook` because it gives me more control over the location where it appears inside my user configuration files: `(add-hook 'emacs-startup-hook (lambda () (split-window-right) ))` . And, of course, you have all the options in the world to put inside it -- e.g, `split-window-vertically`; `split-window-horizontally`; do the hokey pokey and turn yourself around . . ., etc. – lawlist Nov 24 '13 at 00:11
  • edited for better clarity. – username_4567 Nov 24 '13 at 05:42
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    Please specify exactly how you normally "open a new buffer" so that we can understand the exact result you want to achieve -- i.e., what are the exact steps that you take when "opening a new buffer". For example, are you using something like `(find-file "foo.txt")` or `(get-buffer-create "foo.txt")`? Also, do you want one window on the left and one window on the right? Or, do you want one window on top, and one window on bottom? And which window do you want your new buffer to appear in -- top, bottom, left, or right? And what do you want to appear in the other window? – lawlist Nov 24 '13 at 07:17
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    Also, what happens when you already have two windows open and you open a new buffer? Do you want 3 windows or 4 windows total, or do you want the new buffer to take over an existing window -- if so, what window should it take over -- left, right, top or bottom -- and what buffer should appear in the other window when opening a new buffer? There are quite a few options based upon your personal preferences. – lawlist Nov 24 '13 at 07:27
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    possible duplicate of [Setting Emacs Split to Horizontal](http://stackoverflow.com/questions/2081577/setting-emacs-split-to-horizontal) – Tony Oct 03 '14 at 11:19

4 Answers4

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You know that you can do this manually with C-x 3 right? So we can use this fact to learn how to add the command to do this to .emacs.

We just need to find out what the function is. So let's do C-h k C-x 3 to find the help for C-x 3. That shows:

C-x 3 runs the command split-window-right, which is an interactive compiled Lisp function in `window.el'.

So, open .emacs (C-x C-f ~/.emacs), go to the end of the file and add:

(split-window-right)

Then save the file, restart emacs and it should work. I just tested it.

Robin Green
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    Every time I open a new buffer, it should split the current window vertically. and btw this says "An error occurred while loading `~/.emacs" – username_4567 Nov 24 '13 at 05:36
  • @username_4567 you must have made a mistake because I don't get an error. What is your error? – Robin Green Nov 24 '13 at 08:02
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    Has `split-window-right` been around a lengthy period of time going back several Emacs versions? If it has been (i.e., if the issue is not related to an unrecognized function available only in subsequent Emacs versions), then *yes*, there is/are one *or more* error(s) higher up in the user `.emacs` file. – lawlist Nov 24 '13 at 14:53
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    This answers how to open a new *window*, but not the OP's question of how to open a new buffer in a vertically split window. That's different. `C-x 3` splits the window vertically, and `(split-window-right)` just makes Emacs always open with two windows, vertically split. Right? – James Apr 24 '18 at 17:11
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I don't remember the exact route I followed to get this, but I have the following configuration to suggest to Emacs that it should split the frame vertically rather than horizontally when Emacs has the choice (eg when bringing up help).

This seems to work fine on my widescreen monitors.

(setq split-height-threshold nil)
(setq split-width-threshold 160)
Stuart Hickinbottom
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3

Add This to .emacs to split windows vertically as default opening a new buffer in other windows

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

From this post on reddit you can set this explicitly for ediff.

(custom-set-variables
 '(ediff-window-setup-function 'ediff-setup-windows-plain)
 '(ediff-diff-options "-w")
 '(ediff-split-window-function 'split-window-horizontally))

This has the advantage that it doesn't impact other splits.

ideasman42
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