dumb-diff

About

Dumb Diff is an Emacs package for fast arbitrary diffs.

Calling dumb-diff will create two comparison buffers on top and one result buffer on the bottom. Every time you call dumb-diff it will update the result buffer and show the UI. You can use dumb-diff-set-region-as-buffer1 and dumb-diff-set-region-as-buffer2 to copy the content of selected regions directly into the buffer without needed to call dumb-diff first.

Why?

I often need to see the diff of arbitrary content that is either not in a file or is only part of one. For instance, I'll have a string somewhere in a file, and then someone will send me an edit for it. I have often found this situation awkward, so I made this. Similar functionality is somewhere in the ediff package and elsewhere. See alternatives.

How it works?

Dumb Diff uses your built-in diff program against dynamically created temporary files. The diff binary and its arguments are customizable via dumb-diff-bin-path and dumb-diff-bin-args.

Installing

It's available on MELPA: M-x package-install dumb-diff

.emacs options

• (setq dumb-diff-on-set-show-diff-only t) If using a set-region-as-bufferN, when t will only show the diff result buffer while nil will show the comparison buffers and diff result buffer. (defaults to t)
• (setq dumb-diff-clear-buffers-on-quit t) When t, quitting dumb diff will clear the comparison and result buffers. (defaults to t)

use-package example configuration.

(use-package dumb-diff
  :bind (("C-c d" . dumb-diff)
         ("C-c 1" . dumb-diff-set-region-as-buffer1)
         ("C-c 2" . dumb-diff-set-region-as-buffer2)
         ("C-c q" . dumb-diff-quit))
  :ensure t)

I personally use use-package together with hydra.

Alternatives

Potential alternative packages for emacs:

• ediff