rsync of STDIN to a file.

[Matt McCutchen]

On Fri, 2009-11-20 at 17:35 +0000, Mark Young wrote:
> Can you point me at any usage examples with rdiff. I've searched quite
> a bit and apart from the cygwin man page and the "rdiff -?" usage
> message I'm unable to find enough information for me to see how to use
> it successfully.

Yes, the man page is very sparse; it ought to include an example of the
complete process.  In the meantime, I'll provide one here.  Starting
from src/file and dest/file :

(cd dest && rdiff signature file file.sig)
cp dest/file.sig src/
(cd src && rdiff delta file.sig file file.delta)
cp src/file.delta dest/
(cd dest && rdiff patch file file.delta file.new)

Now dest/file.new is a copy of src/file .  For more about how this
works, see:

http://rsync.samba.org/tech_report/node2.html

For remote operation, the "cp" commands should be replaced with an
appropriate network copy command, perhaps even rsync itself.

> In particular I'm not sure I see how it would be used in my scenario.
> Currently there's no local copy of the backup image file.

See above.  You would also pipe your tar command to "rdiff delta",
replacing the "file" argument with "-".

-- 
Matt