Re: Extracting indiviual files or directories from XYZ.tar.xz - Possible?
Michael Paoli (HE12025-08-09):
> I don't think there's any tar format that has an "index" or the like,
> it's generally just a tar header,
There is no global tar header.
> then for each file (of any type),
> specific header for that, and any associated data,
Yes.
> and I think there's
> also some type of end marker or the like, perhaps with a bit of metadata
> at the end too.
Only padding of 0 until the next multiple of 512 octets.
> And there may be some type of marker or the like at
> the end of the archive too.
Again, only more padding of 0.
> But I think that's basically it.
Yes.
> So, even if tar is requested to restore a single file,
> and has gotten to the point in archive where it's extracted that file,
> that doesn't mean it can quit at that point.
It could observe: hey, decompression library says there is a new block,
100K compressed, 5M uncompressed; I am 2M into a 10M file I do not want
to extract, let me skip that block, 100K of compressed input, I am now
7M into that file I do not need to extract.
But as I said, it does not do that, and that would be useless because xz
files do not have block in practice.
Regards,
--
Nicolas George
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