Interrupting a read

[byrne%TARTAN at CMU-CS-C.ARPA]

From:  Steve <byrne%TARTAN at CMU-CS-C.ARPA>

OS: 4.2BSD
Problem:
	I want to read from a terminal a certain number of
	characters within a given time.  If the read doesn't get
	the proper number of characters within the given time
	limit, I want the read to terminate, and possibly signal
	some sort of error (just returning -1 as its value would be
	find).  

	This worked in 4.1, but I can't figure out a way to make
	it work under 4.2.  Any clues?

steve
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