C:\test\DBMNested>p1
[0] Perl> sub getChecksum($) {
        my $in = shift;
        our $check = 0;
        $in =~ m/(?:(.)(?{$check += ord($1);}))*^/;
        return $check;
};;
print getChecksum( 'foo' );;
324

print getChecksum( 'foo' );;
324

print getChecksum( 'foobar' );;
633