loopdir¶

Example script to loop over all the objects of a ROOT file directory and print in Postscript all the TH1 derived objects. This script uses the file generated by tutorial hsimple.C

Author: Rene Brun
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Friday, March 24, 2023 at 10:55 AM.

In [1]:

TFile *f1 = TFile::Open("hsimple.root");
TIter keyList(f1->GetListOfKeys());
TKey *key;
TCanvas c1;
c1.Print("hsimple.ps[");
while ((key = (TKey*)keyList())) {
   TClass *cl = gROOT->GetClass(key->GetClassName());
   if (!cl->InheritsFrom("TH1")) continue;
   TH1 *h = (TH1*)key->ReadObj();
   h->Draw();
   c1.Print("hsimple.ps");
}
c1.Print("hsimple.ps]");

Info in <TCanvas::Print>: ps file hsimple.ps has been created
Info in <TCanvas::Print>: Current canvas added to ps file hsimple.ps
Info in <TCanvas::Print>: Current canvas added to ps file hsimple.ps
Info in <TCanvas::Print>: Current canvas added to ps file hsimple.ps
Info in <TCanvas::Print>: ps file hsimple.ps has been closed