how do you time-out on a read?

[JPAYNE at BBNG.ARPA]

But with the new signal mechanism, sigset and sigsys stuff, if no IO has
taken place at the time of the interrupt, the read/write is restarted.
I can't decide whether this is a feature or a misfeature.  What if a 
program, like an interpreter, is sitting in a read-eval-print loop and 
the user types the interrupt character.  The program does what it does with
the interrupt and then goes back to that same read!  If you don't want the
read to be restarted, you use the old signal mechanism.  But the old signal
mechanism allows recursive traps and all that bad stuff ...

(I don't know how new or old any of this stuff is on the VAX.  We recently got
2.81 up on our PDP11/70)

Shouldn't there be a way to specify what you want?