UNIX for Advanced & Expert Users

You mean like...
(that xkcd comic that I can't link to as I haven't made 5 posts yet)

Actually, that's how I got the data onto the HD in the first place...taking it on a train and leaving it with someone else over a weekend. I'll discuss cutting out the middleman in future with them, but I suspect there will be issues with access control on our respective systems (ie I might have to get the train there to log in for him, or vice versa).

Thanks Rbatte1!

One slight modification
cd source_directory tar -cvf - . | rsh target_gateway "ssh -X target_server; cd target_directory ; tar -xvf -"seems to be working

I would never have guessed that a dot and a hypen would descend through all the subdirectories. How do you learn this type of syntax?

The hyphen has nothing to do with that. Neither does the dot, really. tar is simply recursive by design. Give it one folder and it'll archive all the contents. I don't think you can even turn that off.

There literally is a folder named dot no matter where you are. It's just short form for "current folder" and will work with any program that uses folders. Try ls . There's also a .. which means "one folder up from the current folder". These folder shortcut things are an extremely old feature and found nearly everywhere.

The hyphen tells tar to write to standard output instead of to an actual file. It'd spew it straight to the terminal if you didn't redirect it. But since you put a pipe after it, it puts it straight into rsh.

On the other end, where you extract with tar, the same - is taken to mean "read from standard input". And what is standard input? If you didn't pipe anything into it, it'd be reading straight from your terminal, but because of the pipe, it's reading from the program before -- tar.

So in this manner you create a tarball, feed it over the network, and extract it on the other end.

If rsync is available I would use it, I had in the past tar | rsh conveyer fail when dealing with several gigabytes worth of data, but never had problems with rsync