How to pass a variable to a TSelector

ROOT
1

Hello,
let’s say I generated a Selector using the command MakeSelector(“Whatever”).
Then let’ s say I have a script which uses the Selctor mentioned above, using the command

TChain *ch = new TChain("events");
 [..]
 ch->Process("Whatever.C+");

How can I pass a variable to be used inside the Begin(TTree * /tree/) function of the Selector?
Namely, how should I modify the selector Whatever in order to let it accept as “input” a variable given by the script I mentioned above?
How should I modify then the script?
I guess something like:

TString variable="no-clue";
ch->Process("Whatever.C(variable)+");

Thanks for your help and attention

2

Can it be that you’re looking for something like a “public_attribute” trick shown in the “ROOT User’s Guide” -> “Trees” -> “Using TTree::MakeSelector”?

3

Yes, thanks a lot. It actually helped.
Cheers