Show the difference between two files

Question

How to implement functionality in emacs to show the difference between two files opened in two buffers? Kind of like revdiff when using mercurial.

Answer 1

Emacs has ediff that can distinguish between two files. To use it, simply Mx ediff and specify the two files you want to split.

Answer 2

By the way, if you want to see the differences between two blocks of text in the same buffer, you can do it as follows: - make sure that smerge mode is loaded (for example, Mx load-library RET smerge-mode RET ). - go to the beginning of the first block, C-SPC - go to the beginning of the second block, C-SPC - go to the end of the second block, Mx smerge-makeup-conflict RET - then you can use Cc ^ R or Cc ^ = to see the differences. Note that this works better if the two blocks are pretty much consistent.

Answer 3

Mx diff does this.

See the docs for more details: http://www.gnu.org/software/emacs/manual/html_node/emacs/Comparing-Files.html

Answer 4

I also found that comparison windows do an amazing job, cyclically changing the differences in open buffers.