#include <string>
#include <vector>
#include <fstream>
#include <iostream>
#include <math.h>
#include <TFile.h>
#include <TDirectory.h>
#include <TCollection.h>
#include <TH1.h>
#include <TH2.h>
#include <TKey.h>
#include <TROOT.h>
#include <TClass.h>

// function declarations_________________________________________________________________
void readDir(TDirectory *dir);
//_______________________________________________________________________________________
void readDir(TDirectory *dir)
{
	TDirectory *dirsav = gDirectory;
	TDirectory *currentDir = gDirectory;
	TIter next(dir->GetListOfKeys());
	TKey *key;
	while ((key = (TKey*)next()))
	{
		// if the Key is a folder read the directory and skip the rest of the block
		if (key->IsFolder()) {
			dir->cd(key->GetName());
			currentDir = gDirectory;
			readDir(currentDir);
			dirsav->cd();
			continue;
		}
		// so the key is not a folder
		TClass *cl = gROOT->GetClass(key->GetClassName());
		if (!cl->InheritsFrom("TH1")) continue;
		TH1 *h = (TH1*)key->ReadObj(); // lädt das Objekt aus der Datei in den Speicher
		std::string histname = h->GetName();
		size_t pos = histname.find("_uncorr");

		if(pos!= string::npos){
			std::string name_to_find = histname.substr(0,pos);
			TH1 *hist_to_find = 0;
			gDirectory->GetObject(name_to_find.c_str(),hist_to_find);
			
			// AS SOON AS YOU UNCOMMENT THE NEXT LINE SCRIPT CRASHES
			//if(hist_to_find)
			//	std::cout << hist_to_find->GetName();
			
			hist_to_find->Draw();
		}
	}
}