Xref: utzoo comp.os.vms:33587 comp.lang.c:34783 rec.games.programmer:2698
Path: utzoo!mnetor!tmsoft!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!wuarchive!emory!gatech!uflorida!sparky.cis.ufl.edu!corwin
From: corwin@sparky.cis.ufl.edu (Jack Rusher)
Newsgroups: comp.os.vms,comp.lang.c,rec.games.programmer
Subject: Re: VAX-C immediate char reading
Keywords: VAX-C VMS i/o immediate
Message-ID: <25930@uflorida.cis.ufl.EDU>
Date: 15 Dec 90 00:18:49 GMT
References: <1990Dec14.191104.7874@athena.mit.edu> <1990Dec14.195737.22164@nntp-server.caltech.edu>
Sender: news@uflorida.cis.ufl.EDU
Reply-To: corwin@sparky.cis.ufl.edu (Jack Rusher)
Distribution: na
Organization: U of Florida. Computer Science Dept.
Lines: 33

The best way to perform the sort of I/O you have mentioned is to
set up an $QIO call that specifies an AST handler to call when your
routine gets input.

As Per (excuse my pseudo-code):

volatile char Ch;

ProcessChar()
{
   DoStuff(Ch);
   $QIO (IO$READVBLK, Channel, etc, Ch, etc, ProcessChar, etc);
}

main()
{
   $QIO (IO$READVBLK, Channel, etc, Ch, etc, ProcessChar, etc);
   while (!done)
      do_non_player_stuff();
}


   Which will call "ProcessChar" when there is stuff to input, and 
will continue to execute in the meantime.  Check out the docs for
$QIO, $ASSIGN and the other stuff in the System Services section of
the VMSHELP files for more information on exact syntax.

   If you do not grok what it has to say, do not dispair!  There will
soon be another solution to your problem.  The GameLib project here
at UF is producing an object library for just this sort of thing.

-Jack Rusher,
corwin@ufl.edu