This should be quite nippy. 
my $str = '1234567812345678';
$str =~ s/(.{8})/reverse $1/eg;
print "str: $str\n";

__output__

str: 8765432187654321

[download]
HTH

_________
broquaint

In reply to Re: Reversing chunks in a string (bits of byte in a bitstring) by broquaint
in thread Reversing chunks in a string (bits of byte in a bitstring) by spurperl

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