Querying tty input with ioctl

[pedicone at mozart.steinmetz]

I have an application in which I need to query tty input from a C program.
I can't use getc because I have other processing that must continue.  It
seems that I have to use ioctl in order to query the terminal directly.
Is this the best way to do it?  If so, does anybody have an example of
a driver that uses it.  If this is not the best way, what should I do?
I'm using a Sun 3/260.

Any insight would be appreciated!

John