Checking for file with no keys

Hi,

I am using root 4.00.03 and I am running over a number of files and I want to check when they have no keys.

TFile f(“kGammaBox3040/100072/minEcut/ntup_0.15.root”)
Warning in TFile::Init: file kGammaBox3040/100072/minEcut/ntup_0.15.root has no keys
f.IsZombie()
(const Bool_t)0
f.TestBit(TFile::kRecovered)
(const Bool_t)0
f.IsOpen()
(const Bool_t)1

Is there perhaps some other way to check whether a file has keys that I don’t know about?

use f.GetNkeys() (TDirectory::GetNkeys)

Rene