while (my $text=<$testo>){
    for my $key (keys %hash){
      my $value = $hash{$key};
      my $arrkey=$key." ";  
      my $count = 0;
      $count += () = /\b$key\b/ig while <>;
      print $conteggio "$arrkey) => $count\n";
    } ;
  } ;

##</code><code>##

  my $count = () = $text =~ /\b$key\b/ig ;

##</code><code>##

  my $count = 0 ; while ($text =~ /\b$key\b/ig) { $count++ ; } ;