On Mon, 1 Jun 2020, Rob Pike wrote:

>  I’m not quite sure why the Research lineage did not include
>  non-blocking behaviour, especially in view of the man page comments.
>  Maybe it was seen as against the Unix philosophy, with select()
>  offering sufficient mechanism to avoid blocking (with open() the hard
>  corner case)?
> 
> That's it. Select was good enough for our purposes.

After being dragged through both Berserkley and SysVile, I never did get 
the hang of poll()/select() etc,,,

-- Dave