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This is an excerpt from the latest version perlfaq4.pod, which
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4.74: How do I print out or copy a recursive data structure?

The "Data::Dumper" module on CPAN (or the 5.005 release of Perl) is
great for printing out data structures. The "Storable" module on CPAN
(or the 5.8 release of Perl), 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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