diff current working copy of a file with another branch's committed copy

Question

I have a repo with file foo in the master branch. I switched to bar branch and made some changes to foo. How can I now run a git diff

Answer 1

The following works for me:

git diff master:foo foo

In the past, it may have been:

git diff foo master:foo

Answer 2

You're trying to compare your working tree with a particular branch name, so you want this:

git diff master -- foo

Which is from this form of git-diff (see the git-diff manpage)

   git diff [--options] <commit> [--] [<path>...]
       This form is to view the changes you have in your working tree
       relative to the named <commit>. You can use HEAD to compare it with
       the latest commit, or a branch name to compare with the tip of a
       different branch.

FYI, there is also a --cached (aka --staged) option for viewing the diff of what you've staged, rather than everything in your working tree:

   git diff [--options] --cached [<commit>] [--] [<path>...]
       This form is to view the changes you staged for the next commit
       relative to the named <commit>.
       ...
       --staged is a synonym of --cached.

Answer 3

Also: git diff master..feature foo

Since git diff foo master:foo doesn't work on directories for me.

Answer 4

git diff mybranch master -- file

should also work

Answer 5

git difftool tag/branch filename

Answer 6

To see local changes compare to your current branch

git diff .

To see local changed compare to any other existing branch

git diff <branch-name> .

To see changes of a particular file

git diff <branch-name> -- <file-path>

Make sure you run git fetch at the beginning.