EOF with pipes.

[jpayne%bbn-vax at sri-unix.UUCP]

From:  Jonathan Payne <jpayne at bbn-vax>

It sure would be neat if EOF's could be sent down pipes.  I've heard a
rumor that you can do that in 4.2.  Is that true?  Something like
	write(fd, nul, 0);
or something like that anyway.  Is it actually hard to implement in
any version of UNIX?  Doesn't seem so.  Wouldn't be very compatible
with the rest of the world ...