How to test if a key has been hit w/o waiting for a key ?

[Chris Torek]

>In article <1990Apr24.000717.7882 at cunixf.cc.columbia.edu>
>gm at cunixd.cc.columbia.edu (Gary Mathews) writes:
>>I want to do some computation and be able to stop by a key pressed by the
>>user.

(As I said already, this cannot be done *portably*.  Given a definition
for `key pressed' and `user', it can usually be done; and it can usually
be done without resorting to writing assembly code, as I once did on VMS
so as to bypass the Pascal runtime library....)

In article <8281 at cognos.UUCP> jimp at cognos.UUCP (Jim Patterson) writes:
>        ioctl( stdin->_file, FIONREAD, &count );
>        count += stdin->_cnt;

Be *very* careful with this:
  a. FIONREAD does not exist on all Unix systems, and on some of those
     on which it does exist, it does not quite work right;
  b. stdin probably does not have a _file and/or _cnt structure member
     on some machines.  (If you disagree, try porting to 4.4BSD when
     it comes out.  You may be unpleasantly surprised.)
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris at cs.umd.edu	Path:	uunet!mimsy!chris