git diff --diff-filter=M

Example: show only added , changed, modified files exclude deleted files:

git diff --diff-filter=ACM

https://stackoverflow.com/questions/6894322/how-to-make-git-diff-and-git-log-ignore-new-and-deleted-files

You are looking for --diff-filter=M to show only files *M*odified between the two branches.

From man git-diff

    --diff-filter=[ACDMRTUXB*]

    Select only files that are

        A Added
        C Copied
        D Deleted
        M Modified
        R Renamed
        T have their type (mode) changed
        U Unmerged
        X Unknown
        B have had their pairing Broken
        * All-or-none

    Any combination of the filter characters may be used.

    When * (All-or-none) is added to the combination, all paths are selected if there is any file that matches other criteria in the comparison; if there is no file that matches other criteria, nothing is selected.

https://stackoverflow.com/questions/6879501/filter-git-diff-by-type-of-change