What's the right way to write this: 
defined($exceptions{$user}) ? (join " ",@{$exceptions{$user}}
                            : ""

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...I had initially written @{$exceptions{$user}}, which was short and sweet. But that fails if $user isn't a key of %exceptions. It seems overly complicated and verbose to have to check to see if $exceptions{$user} is defined before treating it as an array reference.

In reply to overcoming undef as Array ref by Anonymous Monk

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