use IO::Select;
print "($$) parent\n";
$| = 1;
my $timeout = 1;
if ( my $pid = open my $fh, "-|" ) {
    print "($$) opened $pid\n";
    my $s = IO::Select->new;
    $s->add($fh);
    my $ready;
    while (not(($ready) = $s->can_read($timeout))) {
        print ".";
    }
    print $/;
    chomp, print "($$) got ($_) from child\n" while <$ready>;                                         
}
elsif (defined $pid) {
    sleep 3;
    print "($$) i am the child and i finished my work\n";
      exit;
}