Try it this way (get last update from the hash as well): 
  my $hash    = RRDs::info( $datafile );
  my $hStep   = $hash->{'step'};
  my $lupdate = $hash->{'last_update'};
  my $mid     = $lupdate % $hStep;
  print( "$lupdate % $hStep = $mid\n" );

In reply to Re^2: implicit numeric conversion isn't by stargrazer
in thread implicit numeric conversion isn't by stargrazer

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