use Fcntl ':mode';

my $mode = ...;
if (S_ISDIR($mode)) {
  # directory
  ...
}

##</code><code>##

my $ssh2 = Net::SSH2->new();
my $sftp = $ssh2->sftp();

my %fstat = $sftp->stat("${testdir}");

my $perm = $fstat{"mode"} & 07777;