Re: 'git diff' against files outside a git repo

> Hi all,
> 
> I'm interested in using 'git diff' on some files that aren't actually
> inside a git repo at all.  Specifically, the --color-words and
> --word-diff-regex are really cool and I happen to have a use for them
> on files that aren't stored verbatim in git.  As a whole, git's
> implementation of diff seems to be the fastest-moving one out there,
> so I'd rather use it instead of another random diff implementation.
> 
> (For the curious: the particular "files" I want to compare are
> actually split into a hierarchical tree of blobs using bup's rolling
> checksum and *then* stored in git.  Obviously I have to reassemble
> them before I can diff them, which is fine and easy, but I then want
> to run 'git diff' against them, which seems to not be so easy.)
> 
> (For the extremely curious: the particular files I want to diff are
> mega-gigantic csv files from database dumps.  Because of bup's tree
> format, I should be able to zoom in on just the overall part of the
> file that has changed, then diff only that, which will be much faster
> than running a diff algorithm against the whole file.  Essentially
> O(log n) vs. the file size.)
> 
> Is there already a way to get 'git diff' to do this?