Re: TAR suggestion...

[Hans-Bernhard Broeker]

Dennis Pund <address@hidden> wrote:

> What I would like to do is:

> foo my.tar.gz | tar -xzOf - | tar -cMf - -L 650000 - | bar

Hmmm.... no, that can't work.  You can't extract archive contents to
stdout and still retain all their filenames to recreate the archive
from them.  A quick look at -xO output will show you why: all the
addition about the files except their contents and maybe their names
are not expressed by it.

But thinking a bit further, I guess the the -A option is the way to
go.  This might be more similar to what you should be trying:

   tar -cMf one_cds_worth -F burn_one_cd_script -L 650000 -A my.tar.gz

This "concatenates" a given tar archive, my.tar.gz, to the end of the
(currently empty or nonexistant ) tar file on the tape.  To make this
work, it may be necessary to first create an empty archive on the tape
and rewind it before doing the above. You may also have to use a
special FIFO file in place of one_cds_worth and have the
"burn_one_cd_script" inform the process on the other end of that FIFO
to close the current CD and ask for a new one.  A simulated remote
tape drive could do this, I guess, as that is also handled by tar
passing on the data to be written to another process via a pipe.  This
process could be what "bar" is in your outline.


-- 
Hans-Bernhard Broeker (address@hidden)
Even if all the snow were burnt, ashes would remain.