Scanning stdin with no pause

[Phil Chadwick]

    >>     I am working with V7 UN*X.  I need a way to scan the standard input
    >> stream for a character, but not wait.
    >
    >This is not supported by 7th Edition UNIX.  You need to add something
    >to your kernel to do this directly; the Rand Corp. empty() call has
    >been distributed by USENIX a long time ago, and more recent approaches
    >include VTIME,VMIN in AT&T UNIX Systems III & V and select() in 4.2BSD.
 
VTIME and VMIN index the control character array in the termio structure
of USG systems.  They appear to be potentially very usefull, but I have
been unable to locate any printed documentation on how to manipulate
c_cc[VTIME] and c_cc[VMIN] to achieve a non-blocking read.  Can anyone
enlighten me please?
----
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