A shell function to remove trailing whitespace from changed lines in a git commit. Intended to be used as part of a git pre-commit hook.

remove-trailing-whitespace-from-changed-lines-in-git-commit

remove_trailing_whitespace_from_changed_lines() {
    patch=$(mktemp --tmpdir remove-trailing-whitespace-patch-XXXXX)
    git diff --cached --no-color --diff-filter=M > "$patch"
    git apply --index --reverse "$patch"
    git apply --index --whitespace=fix "$patch"
    rm "$patch"
}