Re: How can I get a list of checkout history?

From: Jeff King <peff@peff.net>
Date: Feb 15, 2016, 16:56 UTC
Message-ID: <20160215165603.GD25364@sigill.intra.peff.net>
In-Reply-To: <CAHd499D5nMvFQ-eok_3tMZTNp+9JdcMZSL9XrXqkdUNxmRq_eQ@mail.gmail.com>

On Mon, Feb 15, 2016 at 09:18:50AM -0600, Robert Dailey wrote:

Show 15 quoted lines

> As you know, I can checkout the Nth checked out branch via this syntax:
> 
> $ git checkout @{-N}
> 
> Is there a built-in mechanism to get a listing of previously checked
> out refs? Basically, this would be similar to 'history' command in
> linux where instead of actual commands, it lists like this:
> 
> HEAD@{-1}: master
> HEAD@{-2}: topic1
> HEAD@{-3}: 3f556e9 (detached)
> 
> Seems like reflog should be able to do this, and maybe it can, but I'm
> not sure. Any tips? I'd be fine making a convenient alias for this if
> it ends up being a series of piped commands.

The "@{-N}" syntax works by reading the HEAD reflog backwards and grepping for "checkout: moving from ...". The implementation is in grab_nth_branch_switch.

You could do it yourself like:

  git reflog HEAD |
  perl -lne '/checkout: moving from (\S+) to/ and print $1'

That includes detached HEADs, too. If you want just "real" branaches, you could possibly omit entries which match [0-9a-f]{40}. But that's just a heuristic (you _could_ have a branch that matches that).

-Peff