ure with the &rsquo;0&rsquo; mode option or the R6RS open-file-input-port
procedure with a buffer-mode of none, or by calling setvbuf), or (ii)
&rsquo;proc&rsquo; must deal with everything in the port&rsquo;s buffer by calling
drain-input, or by looping on char-ready? before returning.  This is
because otherwise, if the port is buffered, once the port is read from
there may be further characters in the buffer to be dealt with even
though the GIOChannel watch does not trigger because there is nothing
new to 