Re: [Bug-tar] Append and Bzip2 Incompatibility

[Tim Kientzle]

Sean B. Palmer wrote:
> It does not appear that -r works in conjunction with -j:
> ...
> Are they really incompatible? Or is the functionality of using them
> together just broken? Note that -A and -j don't appear to work
> together either.

Practically speaking, they are fundamentally incompatible.

"In theory", bzip2 compression could handle in-place
modification, but it would require that tar have deep specific
knowledge of bzip2 compression.  (It would have to know
how to locate bzip2 compressed blocks, decompress and
modify the final block(s) and then append new blocks.)

If you really need this, you might try bsdtar.
It has a "streaming update" capability that can read
an archive from one file, modify it on the fly and
write the result to another file.  This can handle
routine "append" and "remove" operations even with
compressed archives.

Tim Kientzle