if ($client && (vec($eout, fileno($client), 1) || vec($rout, fileno($client), 1))) {
     my $result = sysread($client, $tbuffer, 1024);
     if (!defined($result) || !$result) { return; }
   }

   if ($target  &&  (vec($eout, fileno($target), 1)  || vec($rout, fileno($target), 1))) {
     my $result = sysread($target, $cbuffer, 1024);
     if (!defined($result) || !$result) { return; }
     }

   while (my $len = length($tbuffer)) {
     my $res = syswrite($target, $tbuffer, $len);
     if ($res > 0) { $tbuffer = substr($tbuffer, $res); } else { return; }
   }

   while (my $len = length($cbuffer)) {
     my $res = syswrite($client, $cbuffer, $len);
     if ($res > 0) { $cbuffer = substr($cbuffer, $res); } else { return; }
   }