my $output='$std | dot |$data| dot '."\n";

while(<>) {
	my $std = $_;
	my $std_dot = $.;

	my $data = <DATA>;
	my $data_dot = $.++;

	chomp $std;
	chomp $data;

	last if $std eq '.';

	$output.=sprintf "%4s |%4s |%4s |%4s\n",
		$std, $std_dot, $data, $data_dot;
}

print $output;
__DATA__
a
b
c
d
e