I may not be explaining myself properly -- I'll try again

Perl can show as an integer values to at least 2**49.

email:> perl -e '$r=2**49;print "$r\n";'
562949953421312
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If I use 'seek/sysseek', I can set the disk pointer to greater than 2**32 byte location in a 32bit disk file in Unix/Linux. I was trying to save 8 octets as a pointer in network order in a database. That database could then be moved back and forth from 32 to 64 and vice/versa. I built the database/script on a 64bit Linux machine and then tried to move to a 32bit AIX machine. The database and script did not work properly.

Thank you

Updated: corrected 'D' to 'd'.

Ah okay. I see what you mean now.

That said, I've previously successfully pack'd >32-bit file offsets using the 'D' 'd' format. It handles files up to at least 4 Petabytes which will easily cover anything I'm going to have to deal with for the foreseeable future.

But I appreciate that it is less portable than a network order quad.

---

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

The start of some sanity?

I looked at the 'D' format, and it would work on machines that have 64bit integer hardware, but I need to support some 32 bit only machines. But you got me thinking, and I used some basic math to get what I need (I hope?).

The following code seems to do what I need:

   use strict;
   use warnings;
   
   my $num4g = 2 ** 32; my $grt4g = 500_000 + $num4g ;
   my $start = $num4g - 50; my $no = 0;
   while ( 1 )
   {  my $no1 = Pack( $start );
      my $result = UnPack( "$no1" );
      if ( $start != $result ) { die "not match"; }
      $start++; $no++;
      if ( $start >= $grt4g ) { print "Okay ( $no )\n"; exit; }
   }
   
   sub Pack
   {  my $input = shift;
      my $lower = $input % $num4g;
      my $upper = int ( $input / $num4g );
      return ( pack("N N", $upper, $lower ) );
   }
   
   sub UnPack
   {  my $input = shift;
      my ( $upper, $lower ) = unpack("N N", $input);
      return ( ( $upper * $num4g ) + $lower );
   }
   
   
   1;
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I profiled the code and 'pack/unpack' sequence is about 2us/call. The 'Pack' is about 16us per call and the 'UnPack' is about 14us per call. Expensive, but I would then get network neutral code to 562TB, and that would be good.

Do you see anything wrong with the code?

Thank you

"Well done is better than well said." - Benjamin Franklin

Thanks, I look into that!

"Well done is better than well said." - Benjamin Franklin