emacs - automatically split frames on creation

Question

I almost always use Emacs in a one-frame, two-window configuration (that is, one OS window with two Emacs windows inside it). I have the default-frame-alist set so that frames appear at the right size, but then I have to manually split them (with C-x 3). Is there a way to tell Emacs to do that automatically when each new frame is created?

EDIT: If I do happen to create a new frame at some point, I want it to be split vertically as well. Therefore, (when window-system (split-window-horizontally)) in .emacs won't do the job, because it only applies to the initial frame. What I think I need is a hook that runs in the context of each new frame after the default-frame-alist is applied.

Answer 1

Just add

(split-window-horizontally)

to your .emacs file.

With C-h k you can check which Emacs function is linked to your shortcut. It's very useful if you are not familiar good enough with Emacs functions.

Answer 2

To prevent from automatical vertical buffer splitting when e.g. visiting an item in a grep buffer the setting

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

is useful.

Answer 3

It's not exactly what you are asking for, but it's a nice way to get two windows side by side.

You can set the variables split-height-threshold and split-width-threshold, to change the behavior of split-window-sensibly. This way every time a new window pops up, say by autocompletion or by pressing o in a dired buffer, the frame gets split horizontally.

;; only split horizontally
(setq split-height-threshold nil
      split-width-threshold 0)

New frames will still start with only one window, but the first time a new window pops up, you will get one window on the left side and another on the right side.