in reply to Unable to unpack a hex string

Actually only the first value is correct. That's because pack and unpack work on byte aligned positions, so the second set of three bits is read at position 8 rather than 3. This is visible if your input data contains something else than zeros: 

use Data::Dumper;
my $counter = 'a0b0c0d0';
my @x= unpack('(B3)(B3)(B2)(B)(B)(B)(B2)(B3)BBBBB(B11)', pack('H*', $c
+ounter));
print Dumper(\@x);
__DATA__
$VAR1 = [
          '101',
          '101',
          '11',
          '1',
          '',
          '',
          '',
          '',
          '',
          '',
          '',
          '',
          '',
          ''
        ];

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FYI, another way to read bits from a string is to use vec, that makes it possible to read N bits from position P.

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Re^2: Unable to unpack a hex string
by BrowserUk (Patriarch) on May 17, 2017 at 09:44 UTC
    FYI, another way to read bits from a string is to use vec, that makes it possible to read N bits from position P.

    Yes, but it also has byte/word/doubleword/quadword alignment restrictions.

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[reply]

      Oh right, thanks. So that's either pack and unpack or binary masking and shifting operations (maybe combined with vec) on integer values then.

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