What's the best way to transfer files (images, media files, etc.) between a
Linux machine and an Apple iPad running iOS 7.1?

It should preferably be achieveable from the shell and amenable to scripting.

I've started looking at http://libimobiledevice.org/ and it appears there are
utilities available from that project, but I'm yet to find a good howto and I
don't know what other options are open and which protocols are available.

Also, I would rather avoid taking any risks that might adversely affect the
device.