Using gitk, can I see the difference between 2 commits?
Not sure if you actually want a diff or if you want the normal gitk representation but only for the commits leading from sha1 to sha2
In the later case you can provide all the normal revision parameters: https://www.kernel.org/pub/software/scm/git/docs/gitrevisions.html
So you can do things like
gitk sha1..sha2or if master got merged into the sha2 branch and you don't want to see the commits that come from master and sha1, is the first commit branched from master use
gitk master..sha2
Unfortunately, gitk doesn't support diff output in that way. :-( You can use git difftool though. It comes with support for a number of tools builtin. For instance, you could do git difftool -t kdiff3 sha1 sha2. It shows the file diffs one at a time. There was talk on the git list about supporting more than just one file at a time via a diff tool, but I'm not sure where that ended up. I haven't seen a patch implementing it yet.