DB<110> %hash = ("fred" => "flintstone", "dino" => undef, "barney" => "rubble", "betty" => "rubble");

  DB<111> use Data::Dumper

  DB<112> print Dumper \%hash
$VAR1 = {
          'barney' => 'rubble',
          'betty' => 'rubble',
          'dino' => undef,
          'fred' => 'flintstone'
        };

##</code><code>##

  DB<115> $length = 0 + keys %hash
 => 4

  DB<116> printf "%10s\t=>%10s\n" x $length, %hash;
    barney	=>    rubble
     betty	=>    rubble
      dino	=>          
      fred	=>flintstone

##</code><code>##

  DB<123> $template = "%10s\t=>%10s\n" x (0 + keys %hash)
%10s	=>%10s
%10s	=>%10s
%10s	=>%10s
%10s	=>%10s

  DB<124> printf $template, %hash;
    barney	=>    rubble
     betty	=>    rubble
      dino	=>          
      fred	=>flintstone