in reply to Re: Calling and interacting with external executable
in thread Calling and interacting with external executable

Yes, open did it, thank you for the suggestion! Here is the code that worked:
open(GERMS, "| $germline") || die "Could not call germline!\n"; print GERMS "1\n"; print GERMS "$map\n"; print GERMS "$ped\n"; print GERMS "out"; close GERMS;