use Net::OpenSSH;
my $ssh = Net::OpenSSH->new($host);
die "Couldn't establish SSH connection: ".$ssh->error if $ssh->error;
my ($in, $pid) = $ssh->pipe_in('bash','-s')
	or die "pipe_in failed: ".$ssh->error;
print $in <<'EOF';
# ...
EOF
close $in or die "close failed";