Well, having a /dev/snarf created by, say,
binding /tmp/blah to /dev/snarf
does not seem to work, because rio ends up
leaving the biggest thing that was in there
(because it does not truncate the file).

I think it assumes that the behaviour of /dev/snarf is that
of rio's, and not that of a regular file.

Regarding the question, I think you answered it. I understand it
provides a snarf if you have different per-rio snarf files.

thanks