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.

First, an apology. When I said 'D' template above, I meant 'd'. (I often mix these up as so many of the other lower/upper case pairings, n is the smaller and N is the larger. But for floating point it is 'f' for the smaller and 'd' for the larger. With 'D' being a later addition that is larger still but not supported on 32- bit).

By using 'd' as your template, you can portably (with restrictions) pack and unpack 'integers' upto 2**52 across the 32-bit/64-bit divide:

\perl32\bin\perl -e"$n=2;$n*=2 for 1..52;$n-=20;print pack'd',$n++ for
+ 1..20" | 
perl -nE"printf qq[%16.f\n],$_ for unpack'd*', $_"
9007199254740972
9007199254740973
9007199254740974
9007199254740975
9007199254740976
9007199254740977
9007199254740978
9007199254740979
9007199254740980
9007199254740981
9007199254740982
9007199254740983
9007199254740984
9007199254740985
9007199254740986
9007199254740987
9007199254740988
9007199254740989
9007199254740990
9007199254740991

[download]

Thus avoiding the need to do custom packing.

Do you see anything wrong with the code?

No. The logic seems fine to me. If you decided to use this in preference to 'd', and will be un/packing long strings of values, then you might want to modify your routines to process variable numbers of values (ie. do the equivalent of 'Q*'), for efficiency.

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?

In reply to Re^7: Will Perl Scripts written on 64 Bit Windows run fine on 32 bit as well? by BrowserUk
in thread Will Perl Scripts written on 64 Bit Windows run fine on 32 bit as well? by Anonymous Monk

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