Need help with signals and IO

[papowell at attila.cs.umn.edu]

I would like a Bombproof Readline function to do the following, under
SYSV and/or 4.2/4.3.  Conditional compilation is fine, but I would
like a version that is portable across both systems.

1. set up a read from a terminal (pipe),  that should time out in
N seconds (N >= 0).
2. if I get a signal (of various flavours),  I would like to either
	A. continue the read until I get a whole line, that is,
		the user enters '\n'.
	B. Discard the entire line that he has typed in.
	C. Save the line that he has typed in, and then possibly
		PUSH IT BACK ON THE INPUT.

A fair time ago there was a discussion of how to write a bomb-proof
version of a read function that would handle the SYSV and 4.2/4.3
signal behaviours.  Of course I did not make a copy of this, and
now I need it.

In addition,  I have been trying to figure out if (2) above is possible,
especially 2.B under SYSV  and 4.2.

Can any  REAL PROGRAMERS help me out with this?
Prof. Patrick Powell, Dept. Computer Science, 136 Lind Hall, 207 Church St. SE,
University of Minnesota,  Minneapolis, MN 55455 (612)625-3543/625-4002