Your code doesn't work because you forgot return $key; in normalize_digits.

Also, I think you can speed things up by using the following: 

my @sorted = map { local $_ = $_; s/^.*\0//; $_ }
             sort
             map { normalize_digits($_) . "\0$_" }
             @data;

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In reply to Re^2: Sorting question by ikegami
in thread Sorting question by perl_seeker

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