keyscan wanted

[Guy Harris]

>As long as the machine in question has select(2), which automatically assumes
>a UNIX with some BSD extensions - SYSV hacks will have to use poll(2) instead.

Unless, of course:

	1) their System V doesn't have "poll" (releases before S5R3
	   didn't have it, unless there was some version that snuck it
	   in as an undocumented feature, say);

	2) their System V doesn't have the device that you're trying to
	   "poll" as a streams device, and doesn't support "poll" on
	   non-streams devices (I've not seen any release from AT&T that
	   1) has *all* its ttys as streams devices or 2) supports
	   "poll" on non-streams devices, although S5R4 may do both).