matija, thank you.

but it's not working. i think it's more complicated than it sounds? i mean, using IO::Select. are we supposed to go into a while loop? too confusing.

but not all hopeless, i think i found another solution. i think i will try bioperl.

anything you want to do, if you search long enough, you will find someone else has already done it.

thanks anyway. take care. see you.