use v5.12; use warnings; use IPC::Run3; my ($cmd, $in, $out, $err); $cmd = 'perl ./server.pl'; open my $fh_in,"|-", $cmd; #my @in; #run3($cmd, \@in); sub out { $fh_in->say(@_); } my $doit; for my $try (2,3,2) { $doit = "$;" x $try; out($doit); out($_) for 1..$try; out($doit); } out("EOF");