use IO::Handle;
  my ($readPIPE,$writePIPE, $pid);
  pipe $readPIPE, $writePIPE;
  $writePIPE->autoflush(1);
  $pid = fork;

  if ( !$pid ) {   # child
    close($writePIPE);
    nonBlockingRead( $readPIPE );
    exit;
  } else { # parent
      close($readPIPE);
      my (n,$s) = (0,0);
      while (1) {
        $s = (int(rand( 50 )));
        sleep (int(rand( 50 )));
        print $writePIPE "Dad: line ",++$n," after $s s\n";
      }
  }

sub nonBlockingRead {
    use IO::Select;
    my $PIPE = ( shift );
    my $SEL = IO::Select->new( $PIPE );
    my @LINES = qw ( ini deafault array size );
    IO::Handle->new_from_fd(fileno( $PIPE ),"r")->blocking(0);

    while ( $SEL->exists( $PIPE ) ) {
      ($sleep,$send) = doWait( $sleep, scalar @LINES );
      @LINES = ();
      foreach my $h ( $SEL->can_read(0) ) {
        push @LINES, ( <$h> );
      }
      foreach my $l ( @LINES ) {
        &doSomething( $l );
      }
    }
}

sub doWait {
    my $sec = (shift);
    my $NoL = (shift); #: every whole min
    $sec = ($NoL>20)?($sec/2):(($NoL< 5)?($sec+1):$sec);
    my $m = 60 - (time%60);
    if ( ( $m - $sec/2 ) < $sec ) {
      sleep ($m-0.2);
      return ($sec, 1); # ok full Min
    } else {
      sleep ($sec);
      return ($sec, 0); # default
    }
  }