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Posted by PerlFAQ Server on March 7, 2008, 3:03 am
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This is an excerpt from the latest version perlfaq4.pod, which
comes with the standard Perl distribution. These postings aim to
reduce the number of repeated questions as well as allow the community
to review and update the answers. The latest version of the complete
perlfaq is at http://faq.perl.org .
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4.73: 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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