Re: [Bug-tar] mtime in x header

[Tim Kientzle]

Michael D. Adams wrote:
> Running tar over the exact same file at two different time isn't
> producing the exact same tar file.
>
> I've tracked this down to the mtime field in the header that has
> typeflag=x.
>
> Questions:
>  (1) Is this behavior in conformance with the POSIX-2001 spec?  I
> haven't seen anywhere that says what the mtime field should be when
> there is an mtime extended header, but other tar/pax implementations
> just fill it with zeros.

I don't think the POSIX spec says anything about this.
You should be able to avoid it, of course, by using
"ustar" format, which does not generate the 'x' entries.

I'm curious which "other tar/pax" implementations
you surveyed?

bsdtar actually uses the same mtime value for
the header of the 'x' entry that it uses for
the regular header.

Cheers,

Tim