open (SUM2,">$ARGV[0].sum.sorted");

my @records;
{
        local $/ = /\n\n/;
        open IN2, "$ARGV[0].sum" or die "Cannot open data file.\n$!";
        while ( my $record = <IN2> ) {
                my @kv_pairs = split /\n/, $record;
                push @records, [@kv_pairs];
        }
        close IN2;
}

print STDERR 'Record count: ', scalar @records;

my @sorted_recs = map { $_->[0] }
                  sort { $a->[1] <=> $b->[1] }
                  map { [ $_, (split /=\s+/,$_->[4])[1] ] }
                  @records;

foreach my $records ( @sorted_recs ) {
        foreach my $record ( @{$records} ) {
                print SUM2 $record;
        }
        print SUM2 "\n";
}

close (IN2);
close (SUM2);