Here are a few other variables for customizing Ediff:
Controls the way you want the window be split between file-A and file-B
(and file-C, if applicable). It defaults to the vertical split
split-window-vertically, but you can set it to
split-window-horizontally, if you so wish.
Ediff also lets you switch from vertical to horizontal split and back
Note that if Ediff detects that all the buffers it compares are displayed in separate frames, it assumes that the user wants them to be so displayed and stops splitting windows. Instead, it arranges for each buffer to be displayed in a separate frame. You can switch to the one-frame mode by hiding one of the buffers A/B/C.
You can also swap the windows where buffers are displayed by typing ~.
Controls how windows are
split between buffers A and B in the merge mode.
This variable is like
ediff-split-window-function, but it defaults
split-window-horizontally instead of
The value is a function to be called to widen the frame for displaying
the Ediff buffers. See the on-line documentation for
ediff-make-wide-display-function for details. It is also
recommended to look into the source of the default function
You can toggle wide/regular display by typing m. In the wide display mode, buffers A, B (and C, when applicable) are displayed in a single frame that is as wide as the entire workstation screen. This is useful when files are compared side-by-side. By default, the display is widened without changing its height.
Controls the way Ediff presents the
default directory when it prompts the user for files to compare. If
Ediff uses the default directory of the current buffer when it
prompts the user for file names. Otherwise, it will use the
directories it had previously used for files A, B, or C, respectively.
t, makes C-h
behave like the DEL key, i.e., it will move you back to the previous
difference rather than invoking help. This is useful when, in an xterm
window or a text-only terminal, the Backspace key is bound to C-h and is
positioned more conveniently than the DEL key.
This variable’s value is a function that Ediff uses to toggle the read-only property in its buffers.
The default function that Ediff uses simply toggles the read-only property, unless the file is under version control. For a checked-in file under version control, Ediff first tries to check the file out.
ediff-make-buffers-readonly-at-startup nil ¶
t, all variant buffers are made read-only at Ediff startup.
The default is
t, meaning that the buffers being compared or merged will
be preserved when Ediff quits. Setting this to
nil causes Ediff to
offer the user a chance to delete these buffers (if they are not modified).
Supplying a prefix argument to the quit command (
reverses the meaning of this variable. This is convenient when the user
prefers one of the behaviors most of the time, but occasionally needs the
However, Ediff temporarily resets this variable to
t if it is
invoked via one of the "buffer" jobs, such as
This is because it is all too easy to lose a day’s work otherwise.
Besides, in a "buffer" job, the variant buffers have already been loaded
prior to starting Ediff, so Ediff just preserves status quo here.
ediff-cleanup-hook, one can make Ediff delete the variants
unconditionally (e.g., by making
ediff-janitor into one of these hooks).
t, the versions of the files being
compared or merged using operations such as
ediff-merge-revisions are not deleted on exit. The normal action is
to clean up and delete these version files.
t. Normally, Ediff grabs mouse and puts it in its
control frame. This is useful since the user can be sure that when he
needs to type an Ediff command the focus will be in an appropriate Ediff’s
frame. However, some users prefer to move the mouse by themselves. The
above variable, if set to
maybe, will prevent Ediff from grabbing
the mouse in many situations, usually after commands that may take more
time than usual. In other situation, Ediff will continue grabbing the mouse
and putting it where it believes is appropriate. If the value is
nil, then mouse is entirely user’s responsibility.
Try different settings and see which one is for you.