GitGoat is a tool for adding RCS-like identification keywords to files in Git repositories.

When I used RCS for a short while, I found one specific feature VERY helpful: ident. It's a command that searches for RCS keywords in a file and displays the keyword and only the keyword.

This is useful for tracking where bugs come from in projects that compile to binaries; you would be able to use ident and it would show the file name, the version, date, and author of the latest change to the file.

Here's an example from NetBSD:

$ ident /bin/cat
/bin/cat:
     $NetBSD: crt0.S,v 1.4 2018/11/26 17:37:45 joerg Exp $
     $NetBSD: crt0-common.c,v 1.23 2018/12/28 20:12:35 christos Exp $
     $NetBSD: crti.S,v 1.1 2010/08/07 18:01:33 joerg Exp $
     $NetBSD: crtbegin.S,v 1.1 2010/08/07 18:01:33 joerg Exp $
     $NetBSD: cat.c,v 1.57 2016/06/16 00:52:37 sevan Exp $
     $NetBSD: crtend.S,v 1.1 2010/08/07 18:01:33 joerg Exp $
     $NetBSD: crtn.S,v 1.1 2010/08/07 18:01:34 joerg Exp $

• git
• sed
• tar and gzip

To add keywords to a file, create a variable that won't be removed upon compilation. For example, in C, you could use:

const char *gitid = "$Git$";

Then, use gitgoat -p <files(s)>, ex. gitgoat -p foobar.c. This will replace the comment with something like this:

const char *gitid = "$Git: 265933eba2ee713d7d6c1f293119e53c59635b13100644 d0627df69573d05d16bdf463691b85d419f10e95 0	src/bracket.c $";

To strip keywords from a file, use gitgoat -s <file(s)>, ex. gitgoat -s foobar.c. This will remove the keywords and restore the keywords to simply be $Git$.

To search for keywords in a binary, use ident <file>. This will show you the keywords in the binary. Note that some binaries might use RCS or CVS keywords. which have the same $ prefix. To hide non-GitGoat keywords, use ident <file> | grep -v '$Git$'.

This tool is designed to do one thing and one thing well: Create & search for keywords. A good example of how to properly use this tool is to find the commit in question, then use git blame to find the author.

The name was a small gag I came up with, thinking about "blaming" someone or a commit for a bug as a scapegoat. Something like that...