# our $Zeropack = "\0" x 4;
# our $MaxNum32bit = 2 ** 32;
# Use:                                     ## n - number of 64bit packed numbers in string
# my @Numbers = UnPack( n, $stringpack );  ## string input, array output
sub UnPack
{  my $todo = shift; my $input = shift;
   my @output = (); my $arno = 0;
   while( $arno < $todo )
   {   my $pack = substr( $input, $arno * 8, 8 );
       if ( substr($pack,0,4) eq $Zeropack )
       {   $output[$arno] = unpack("N", substr( $pack, 4, 4 ) );
       }
       else
       {   my ( $upper, $lower ) = unpack( "N N", $pack );
           if ( ! defined $upper ) { $upper = 0; }
           if ( ! defined $lower ) { $lower = 0; }
           $output[$arno] = ( $upper * $MaxNum32bit ) + $lower ;
       }
       $arno++
   }
   return ( @output );
}