Hadd -v [verbosity] level

this is for ROOT 6.12.06
with x86_64-slc6-gcc62-opt
for the hadd verbosity level I see that:
If the option -v is used, explicitly set the verbosity level;
0 request no output, 99 is the default
can you help me to figure out a very verbose output?
I am not getting anything …
may be I am somehow getting 0 as default so shall I try with 99 ?

I get

$ hadd -v 99 -f o.root $ROOTSYS/tutorials/hsimple.root $ROOTSYS/tutorials/hsimple.root
hadd Target file: o.root
hadd compression setting for all output: 1
hadd Source file 1: /opt/build/root_builds/rootcling.cmake/tutorials/hsimple.root
hadd Source file 2: /opt/build/root_builds/rootcling.cmake/tutorials/hsimple.root
hadd Target path: o.root:/
$ hadd -v 2 -f o.root $ROOTSYS/tutorials/hsimple.root $ROOTSYS/tutorials/hsimple.root
hadd Target file: o.root
hadd compression setting for all output: 1
hadd Source file 1: /opt/build/root_builds/rootcling.cmake/tutorials/hsimple.root
hadd Source file 2: /opt/build/root_builds/rootcling.cmake/tutorials/hsimple.root
hadd Target path: o.root:/
$ hadd -v 1 -f o.root $ROOTSYS/tutorials/hsimple.root $ROOTSYS/tutorials/hsimple.root
hadd merged 2 input files in o.root.
mac-130277:large pcanal$ hadd -v 0 -f o.root $ROOTSYS/tutorials/hsimple.root $ROOTSYS/tutorials/hsimple.root
$ hadd -f o.root $ROOTSYS/tutorials/hsimple.root $ROOTSYS/tutorials/hsimple.root
hadd Target file: o.root
hadd compression setting for all output: 1
hadd Source file 1: /opt/build/root_builds/rootcling.cmake/tutorials/hsimple.root
hadd Source file 2: /opt/build/root_builds/rootcling.cmake/tutorials/hsimple.root
hadd Target path: o.root:/

what kind of information are you looking for?

let’s say that among the files I want to hadd there is a “corrupted”
one
I was hoping that using some suitable -v option one could get a crash
notification in this case rather than hadd just stopping and producing
and incomplete output.root
from your test I also see that there is not much difference in the amount
of “verbosity” I can get using different values of -v

so many thanks a sorry for the “newbie” question

That “should not” happen, it should always say something (more or so useful) independently of the verbosity level.

get a crashnotification in this case rather … producing and incomplete output.root

If there is a corrupted input files, it is more or unavoidable that the output will incomplete … ?

from your test I also see that there is not much difference in the amount of “verbosity” I can get using different values of -v

At least it can help you narrow down which files is the one provoking the (silent) crash.