use Text::xSV;

my $parser = Text::xSV->new;
$parser->open_file( $datafile );

my @headers = $parser->read_header;
shift @headers; # Remove the # field.
my $user_header = shift @headers;

my $data;
while ( $parser->get_row ) {
    my $user = $parser->extract( $user_header );
    $data->{ $user }{ @headers } = [ $parser->extract( @headers ) ];
}