how can I get filename from file descriptor?

[Doug Gwyn]

In article <14280 at super.ORG> rminnich at pacific.UUCP (Ronald G Minnich) writes:
-In article <10850 at smoke.BRL.MIL> gwyn at brl.arpa (Doug Gwyn) writes:
->If your pipe implementation is any good (most are not), simply write 0
->bytes to it.
-Well, now i am real curious. I tried this about 6 years ago on 
-several unices, mostly on vaxes and 11s and such and a Fortune machine,
-and i never saw a zero-length write make it through to a read.
-So, anybody ever had this work? It would be kind of neat if it did...

I did say that most pipe implementations don't support this.
Back in the days of Sixth Edition UNIX, several sites implemented
"pipe internal EOF".  It's clear that streams COULD implement this;
I don't know whether or not the various flavors of streams do.
Personally I think they should.