Re: How do I get the file contents from an arbitrary revision to stdout?

From: Jeff King <peff@peff.net>
Date: Oct 8, 2021, 20:02 UTC
Message-ID: <YWCj6NqMrxksN1V8@coredump.intra.peff.net>
In-Reply-To: <YWCFFcNeNVTYcELN@ACM>

On Fri, Oct 08, 2021 at 05:51:17PM +0000, Alan Mackenzie wrote:

Show 7 quoted lines

> I would like there to be a command something like:
> 
>     $ git cat bar-branch -- foo.c
> 
> ..  Is there such a command, and if so, what's it called and how do I use
> it?  I assumed it might be git cat-file, but I couldn't get it to work,
> and couldn't understand it's man page.

Konstantin pointed you at git-show, which is what I would have used. But I just wanted to mention that you were on the right track. The invocation you wanted was:

  git cat-file blob bar-branch:foo.c

or:

  git cat-file -p bar-branch:foo.c

(the "-p" is "pretty-print based on the object's type", so the two are equivalent).

> Where might I have found this information for myself?

You found the cat-file manpage, which I agree is a bit thick. An Examples section would probably help a lot.

The other thing that might have helped is the gitrevisions(7) page, especially the <rev>:<path> entry. Your example above to use "<revs> -- <pathspec>" was a good thought, but the path there is for limiting diffs and traversals. What you want here is to specify the name of a single object, and gitrevisions gives all the ways to do that.

-Peff