From mboxrd@z Thu Jan  1 00:00:00 1970
From: "=?ISO-8859-1?Q?Santi_B=E9jar?=" <sbejar@gmail.com>
Subject: Re: current repository hash
Date: Mon, 16 Jun 2008 14:15:14 +0200
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To: "Alf Clement" <alf.clement@gmail.com>
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On Mon, Jun 16, 2008 at 13:51, Alf Clement <alf.clement@gmail.com> wrote:
> Hi all,
>
> I want to compile the current repository hash id into my program, to
> be able to checkout later this
> id an see the exact files for the compile. It should flag if there are
> currently modified files in the
> directory tree.

You can look at how git does it:

http://git.kernel.org/?p=git/git.git;a=blob;f=GIT-VERSION-GEN;hb=HEAD

>
> What would be the best command to get a unique identifier?

"git rev-parse HEAD" for a unique identifier,
but "git describe" is more convenient/useful.

> Do I need the 40 digit hash id?

Normally 7 or 8 are sufficient.

> How can I make sure that a shorter hash id will be unique?

You can't. Even the 40 digit hash is "only" cryptographically unique.
But within a project 7 or 8 digits are unique enough for practical
use.

Santi