You are in the land of a reference to a hash of hashes. If you are just learning the language and the idioms are unfamiliar to you, you might explicitly dereference first off to simplify

read perldoc perlref

my $ref = $ue->filinfo;
my %HoH = %{$ref};
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Then you have a hash or hashes which is a hash in which the keys are the filenames and the values are hash references.

the canonical print idiom from perldoc perdsc is: (although your taste may differ once you develop it):

 foreach my $filename ( keys %HoH ) {
            print "$filename: { ";
            for my $key ( keys %{ $HoH{$filename} } ) {
                print "$key =$HoH{$filename}{$key} ";
            }
            print "}\n";
        }
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