How to transfer file descriptors with UNIX domain sockets?

[BURNS,JIM]

in article <1990Jul01.130157.3627 at virtech.uucp>, cpcahil at virtech.uucp (Conor P. Cahill) says:
>>in article <1421 at tub.UUCP>, net at tub.UUCP (Oliver Laumann) says:
	[code deleted]
> The system knows because the person, or persons, that added that capability
> to the sockets code ensured that the file descriptor that was passed became
> a valid file descriptor in the process that received it.

I'm sure that it *can* be done - my question is what was it in Oliver
Laumann's code that informed the kernel that what was in the message was a
file descriptor?
-- 
BURNS,JIM
Georgia Institute of Technology, Box 30178, Atlanta Georgia, 30332
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