Can I see changes before I save my file in Vim?

Question

I use Vim. I open a file. I edit it and I want to see what I\'ve edited before I save it.

How can I do this in Vim?

Answer 1

You can make vim create a last backup and original backup with:

:set backup
:set patchmode=.orig 

Thereafter, you can open them in a split:

:vsp %:p~ or :vsp %:.orig

And from there do:

:vimdiff in each buffer

If you're dead set on no leftovers but want vimdiff, you could also do:

ggVGy    # copy the whole buffer
:vnew    # open a split
CTRL-W w # switch to it
shift-P  # paste at start

and then do :diffthis on each split