Re^8: Equivalent of unpack 'q' with 32-bit Perl (a8)

RonW,

If you really need to convert the whole digest to an integer

I just need to duplicate the result of unpack('q', md5($thing)) on 32bit Perl. I wrote something that works at home (see this thread) but it doesn't seem to work at work and I can't understand why.

Cheers - L~R

Comment on Re^8: Equivalent of unpack 'q' with 32-bit Perl (a8) Download Code

Replies are listed 'Best First'.
Re^9: Equivalent of unpack 'q' with 32-bit Perl (a8) by RonW (Parson) on Sep 08, 2016 at 16:34 UTC
This seems to do what you are asking: `#!perl use strict; use warnings; use Digest::MD5 qw(md5 md5_hex); use Math::BigInt; my $foo = 'hello, world!'; my @v = unpack('q', md5($foo)); printf "%x %x\n", @v; my $h = substr(md5_hex($foo),0,16); # get first 8 bytes (pairs of hex +digits) my @w = reverse $h =~ /(..)/g; # split out the bytes and reverse +the order my $w = join('', @w); my $q = Math::BigInt->from_hex($w); print $q->as_hex();` [download] I was surprised that it was necessary to reverse the bytes to get the same result as `unpack('q', md5($foo))` but that's what it took.	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re^9: Equivalent of unpack 'q' with 32-bit Perl (a8)
by RonW (Parson) on Sep 08, 2016 at 16:34 UTC

This seems to do what you are asking:

#!perl
use strict;
use warnings;
use Digest::MD5 qw(md5 md5_hex);
use Math::BigInt;
my $foo = 'hello, world!';
my @v = unpack('q', md5($foo));
printf "%x %x\n", @v;
my $h = substr(md5_hex($foo),0,16); # get first 8 bytes (pairs of hex 
+digits)
my @w = reverse $h =~ /(..)/g;      # split out the bytes and reverse 
+the order
my $w = join('', @w);
my $q = Math::BigInt->from_hex($w);
print $q->as_hex();
[download]

I was surprised that it was necessary to reverse the bytes to get the same result as unpack('q', md5($foo)) but that's what it took.

[reply]
[d/l]
[select]