std::cout << gSystem->WorkingDirectory() << std::endl;
TFile *file = TFile::Open("hsimple.root");
if (!file){
   std::cerr << "Input file not found.\n";
   return ;
}
TTree *ntuple = nullptr;
file->GetObject("ntuple",ntuple);
std::string s1(__FILE__);
TString dir = gSystem->UnixPathName(s1.substr(0, s1.find_last_of("\\/")).c_str());
ntuple->Draw(dir+"/hsimpleProxy.C+");