sub addSecondary
{
	my ($email, $secondary) = @_;

	open my $input,  '<', 'registration.dat';
	open my $output, '>', 'registration.tmp';
	
	while (<$input>)
	{
		chomp;
		my $line = $_;
		if ($line =~ /$email/)
		{
			$line =~ s/nodata/$secondary/gi;
		}
		
		print $output "$line\n";
	}
	
	close $input;
	close $output;
	unlink 'registration.dat';
	rename 'registration.tmp' 'registration.dat';
}

##</code><code>##

use File::Slurp qw(:edit);

sub addSecondary
{
	my ($email, $secondary) = @_;

	edit_file_lines
		{ s/nodata/$secondary/gi if /$email/ }
		'registration.dat';
}