Re: Testing for commit reachability through plumbing commands

From: Jeff King <peff@peff.net>
Date: Mar 6, 2014, 20:23 UTC
Message-ID: <20140306202319.GB29659@sigill.intra.peff.net>
In-Reply-To: <CACPiFCJLyE6XC9dY_eawe2y9gS4YsPdTbqkKAd0dcPXd5-eMCg@mail.gmail.com>

On Thu, Mar 06, 2014 at 12:17:34PM -0500, Martin Langhoff wrote:

Show 9 quoted lines

> I have a shell script that trims old history on a cronjob. This is for
> a repo that is used to track reports that have limited "life" (like
> logs). Old history is trimmed with grafts pointing to an empty "root"
> commit.
> 
> Right now, info/graft grows unbound. I am looking for a way to trim
> unreachable grafts, I would like to be able to say something like:
> 
>  git is-reachable treeish

How about:

    git rev-list --objects --all |
    cut -d' ' -f1 |
    grep $(git rev-parse treeish)

Add "--reflog" to the rev-list invocation if you want to catch things referenced by the reflog, too.

If you're looking for a commit, you can drop the "--objects", and it will run much faster.

-Peff