$s3 = Amazon::S3->new({aws_access_key_id=> $access_id,aws_secret_access_key => $secret_key,retry=> 1}); 
     $bucket = $s3->bucket($b) or die $s3->err . ": " . $s3->errstr; 
     $response = $bucket->list_all or die $s3->err . ": " . $s3->errstr; 
     if (@{ $response->{keys} }) { 
          # show the contents 
     }