For most practical purposes, this question is totally useless. But I have a CPAN module Test-Weaken, which detects leaks in arbitrary Perl data structures. It needs to traffic in references to as many Perl data objects as possible. For all the Perl data types except one, I can duplicate a reference, as follows: 

\@{$array_ref}  # ARRAY
\%{$hash_ref}   # HASH
\${$scalar_ref} # SCALAR, REF, LVALUE, VSTRING, Regexp
\*{$glob_ref)   # GLOB, IO, FILEHANDLE
\&{$code_ref}   # CODE

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My question: how do I dup a FORMAT reference?

You can get a format reference with this syntax: $formatref = *foo{FORMAT}. Formats themselves are deprecated and why you'd want a reference to one I don't know, but my purpose is to allow Test::Weaken to be able to deal with whatever data is thrown at it. That data may come from perverse and/or legacy code.

UPDATED: corrected typos.

In reply to How to dereference a FORMAT reference? by Jeffrey Kegler

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