Re: Q about git rev-parse {--is-inside-work-tree, --show-cdup}

From: Jeff King <peff@peff.net>
Date: Dec 3, 2010, 21:20 UTC
Message-ID: <20101203212035.GB2632@sigill.intra.peff.net>
In-Reply-To: <4CF95BDC.60506@dirk.my1.cc>

On Fri, Dec 03, 2010 at 10:06:36PM +0100, Dirk Süsserott wrote:

Show 24 quoted lines

> I wrote some shell scripts that do sth with my git repositories. I place
> my scripts in my ~/bin folder (not in the repo). So the first step in my
> scripts is always to check whether they get called from whithin a git
> repo and bail out if they don't.
> 
> I do this like so:
> 
> ---------------------
> if [ "$(git rev-parse --is-inside-work-tree)" = "true" ] # (1)
> then
>      here=$(pwd)
>      cdup=$(git rev-parse --show-cdup);    # (2a)
>      cdup=${cdup:-"."}                     # (2b)
>      cd $cdup                              # (2c)
> 
>      [do sth useful from the topdir]
> 
>      cd $here
>      exit 0;
> else
>      echo "Not inside a git working tree."
>      exit 1;
> fi
> ---------------------

Since you are writing shell scripts, you may be interested in doing:

  . git-sh-setup
  require_work_tree
  cd_to_toplevel

> 1. Wouldn't it be useful, if "git rev-parse" (1) had an option "-q" that
> simply indicates whether "--is-inside-work-tree" is true by means of the
> return code? Actually it has an option "-q" but that doesn't work with
> "--is-inside-work-tree".

Yeah, in general rev-parse's "-q" is annoying. It only works with checking revisions (like "git rev-parse -q --verify HEAD"), and it probably should apply to a lot more. Patches welcome.

> 2. Wouldn't it be useful, if "git rev-parse --show-cdup" (2a) would
> return a dot "." instead of nothing if we are already in the topdir?
> That would make the steps (2a), (2b), (2c) to a simple "cd $(git
> rev-parse --show-cdup)".

I'm hesitant to change it, as that is a public interface for shell scripts. However, there is also "--show-toplevel" which will do what you want in one line (or just cd_to_toplevel as I mentioned above).

> What do you think? If appreciated, I'd like to work on a patch for (1).

Please do.

-Peff