tar commit header names

tar commit header names

[Daniel Barkalow]

I'm entirely ignorant of pax header stuff, but would it be possible to 
have the pax header specify which project this commit is from (which has 
to come from a git-archive option, clearly). Also, could 
git-get-tar-commit-id have an option to look for more pax headers beyond 
the first? (I'm building tar files by appending multiple archives for 
different projects from git-archive, and I suddenly find the embedded 
commit id is helpful, and surprisingly inaccessible in this context.)

	-Daniel
*This .sig left intentionally blank*

Re: tar commit header names

[René Scharfe]

Daniel Barkalow schrieb:
> I'm entirely ignorant of pax header stuff, but would it be possible to 
> have the pax header specify which project this commit is from (which has 
> to come from a git-archive option, clearly).

Technically, yes.  The commit ID is stored in a comment, more info could
appended to it.  Adding more stuff there would necessitate an ordering
scheme, though.  I'm not sure this is useful enough.  There already is a
nice convention on where to store the project name, description and URL:
in a file named 'README'. :)

> Also, could 
> git-get-tar-commit-id have an option to look for more pax headers beyond 
> the first? (I'm building tar files by appending multiple archives for 
> different projects from git-archive, and I suddenly find the embedded 
> commit id is helpful, and surprisingly inaccessible in this context.)

This could be done, at the cost of git-get-tar-commit-id having to be
able to really parse tar files in order to seek to the end of the first
and thus to the start of the appended one.  Right now it simply reads
the first few bytes, quickly checks if this looks like a tar file and
prints the commit ID, if one is found.

The right place to add generic archive comment extraction capabilities
(with multi-archive support) would be a general purpose archiver like
GNU tar, no?

René

Re: tar commit header names

[Daniel Barkalow]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 1168 bytes --]

On Thu, 29 Mar 2007, René Scharfe wrote:

> Daniel Barkalow schrieb:
> > I'm entirely ignorant of pax header stuff, but would it be possible to 
> > have the pax header specify which project this commit is from (which has 
> > to come from a git-archive option, clearly).
> 
> Technically, yes.  The commit ID is stored in a comment, more info could
> appended to it.  Adding more stuff there would necessitate an ordering
> scheme, though.  I'm not sure this is useful enough.  There already is a
> nice convention on where to store the project name, description and URL:
> in a file named 'README'. :)

Ah, and the comment applies until the next comment, so the common prefix 
of the files in the area with the comment explains it. I was missing what 
the rules for regions of applicability of pax global headers are. Now, if 
I could convince... something... to report what comments apply to what 
files, I'd be set. And that's clearly beyond the scope of git. (Although 
maybe git-get-... should know how to invoke some other utility on a 
multiple-project archive once some such tool is known.)

	-Daniel
*This .sig left intentionally blank*