Re: [Bug-tar] mtime in x header

[Sergey Poznyakoff]

Michael D. Adams <address@hidden> ha escrit:

> (I haven't tested 'g' headers.  I haven't figured out a
> way to get tar to generate them.

A global header is created if you supply at least one global keyword,
e.g.:

   tar --pax-option 'comment=Test archive' -c -f ...

(global keywords are defined using `keyword=value' syntax, as
opposed to `keyword:=value', which defines per-member keywords).

> Your patch works but has a bug.  If I set the time to '@1' or any
> non-zero value it works, but if I set it to '@0' or '1970-1-1
> 00:00:00Z', then it reverts back to placing the tar file's creation
> time in there.

Yes, of course: it was intended as a proof of concept; in the final
version I will definitely not rely on comparison of the timestamp to 0
to decide if it was set.

> Also I don't think C (at least prior to
> C99) will always initialize exthdr_mtime to zero (compilers and OS may
> vary).

Even the very first C compiler would do it: the memory allocated for BSS
was always initialized to zeroes, since the PDP times.

Regards,
Sergey