#!/usr/bin/perl -w
use Relation::Tools qw(read_file read_tsv read_nosql write_file write_tsv write_nosql);

my $add_remove = shift;

my $tr = read_tsv(read_file(\*STDIN));

if ($add_remove eq "-") {
	my ($nr, $fields) = read_nosql(read_tsv(read_file(\*STDIN)));
	while (<STDIN>) {
		print
	}
} elsif ($add_remove eq "+") {
	my $tr = read_tsv(read_file(\*STDIN));
	my $tw = write_tsv(write_file(\*STDOUT));
	my $row = &$tr;
	my @fields = @ARGV ? @ARGV : (0..$#$row);
	my $nw = write_nosql($tw, \@fields);
	&$tw($row);
	while (<STDIN>) {
		print
	}
} else {
	print STDERR <<End;
usage:	header -
	header + [fields]
End
	exit 1;
}