Re: how to determine version of binary

From: Sitaram Chamarty <sitaramc@gmail.com>
Date: May 5, 2012, 11:43 UTC
Message-ID: <20120505114306.GA1498@sita-lt.atc.tcs.com>
In-Reply-To: <jo2jtd$m6c$1@dough.gmane.org>

On Sat, May 5, 2012 at 12:42 PM, Neal Kreitzinger <nkreitzinger@gmail.com> wrote:

> Scenario:  I detect a binary file that is 'dirty'.  I don't know how it got
> there.  However, I know it came from a git repo.  So I calculate the sha1 of
> the binary.  What is the git command to determine which commit that binary

make sure you are using 'git hash-object' to compute the sha, not the system supplied 'sha1sum' or eqvt.

> version first appeared in?  And the last commit that binary appeared in?

Unless it is a frequent need, I would just use git log's --raw option to search for the first 7 digits of the SHA you found above.

For example, a very quick one (which does not count odd situations like the same file appearing multiple times or on other branches, for instance) is:

    git log --raw | less +/$SHA

You'll want a line where the SHA appears as the second SHA, not the first one (in case a later commit changed the file it would also appear as the first sha). Example, I'm looking for "14136eb", so I type in

    git log --raw '--format=%n%ncommit: %h subject: %s' | egrep commit\|14136eb | grep -B 1 14136eb

The output I get back is:

    commit: 1cf062f subject: ACCESS_CHECK split into ACCESS_1 and ACCESS_2; docs updated
    :100755 100755 14136eb... 2a57e2d... M	src/gitolite-shell
    --
    commit: b391000 subject: POST_GIT triggers get 4 more arguments
    :100755 100755 20f4e5d... 14136eb... M	src/gitolite-shell

So the commit that introduced this version of this file is b391000 (1cf062f is a later one where this file got changed to something else).