perldoc -q copy
Found in C:\Perl\lib\pod\perlfaq4.pod
  How do I print out or copy a recursive data structure?
            The Data::Dumper module on CPAN (or the 5.005 release of P
+erl)
            is great for printing out data structures. The Storable mo
+dule,
            found on CPAN, provides a function called "dclone" that
            recursively copies its argument.

                use Storable qw(dclone);
                $r2 = dclone($r1);

            Where $r1 can be a reference to any kind of data structure
+ you'd
            like. It will be deeply copied. Because "dclone" takes and
            returns references, you'd have to add extra punctuation if
+ you
            had a hash of arrays that you wanted to copy.

                %newhash = %{ dclone(\%oldhash) };
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