I have a module implemented as an inside-out object, and I want to generically expose all of its properties (as read-only), via an accessor method. Following the naming conventions from Perl Best Practices, all properties are named %dbh_of, %csv_of, %working_dir_of, etc. As such, I wrote the following method:

sub get {
  my($self,$attr) = @_;
  my $return_val;
  
  # if valid attribute, assign it as a return value
  if($attr =~ m/\A\w+\z/) {
    my $eval_string = sprintf '$return_val = $%s_of{refaddr $self};', 
+$attr;
    eval $eval_string;
  }
  # otherwise, carp a warning
  else {
    carp("Invalid attribute '$attr'");
  }
  
  return $return_val;
}
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The idea behind this is that, given a string value of the name of a property (such as 'working_dir'), it would return the value of that property for the current instance (the value of %working_dir_of{refaddr $self}). This is not working, however, as all I get back from the method is undefs. I've tried replacing the string eval with a symbolic reference, even though IIRC, this could be exploited if attr is provided a raw memory address:

if($attr =~ m/\A\w+\z/) {
  $return_val = ${$attr}{refaddr $self};
}
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Even with this, I'm still getting undefs returned...Any idea what I'm doing wrong, or (better yet) is there a simpler and better way?