nal condition (&rsquo;excpt) is encountered, a pair comprising
(#f . #f) will be returned.  As mentioned above, if an end-of-file
object is encountered after receipt of some but not &rsquo;size&rsquo; bytes, then
a bytevector of length &rsquo;size&rsquo; will be returned as car and the actual
(lesser) number of bytes inserted in it as cdr.  If an end-of-file
object is encountered without any bytes of data, a pair with
eof-object as car and #f as cdr will be returned.
</p>
<p>A port can be made non-blocking 