In article <199709241751.NAA15464@Twig.Rodents.Montreal.QC.CA> you write:
> 
> This would be neat to have (I did a proof-of-concept version of it back
> in the bad old days of 4.3 on a VAX - a pseudofile for which all
> operations ended up being just messages to the master half, a la the
> pty driver), but I think such things should be distinct creatures all
> their own, rather than "just" sockets accessed in an unusual way.

I was just thinking the other day that something like this would be
neat. Especially if it could support mmap()ing by the client side.

There are all sorts of neat uses for something like this. As a random
example, symlink /dev/audio to the client side, and have a program that
listens to the master side and implements the audio interface, writing
everything to an .au file.