Problem with shared library and dlopen?

ROOT
1

I have built a small shared library of ROOT classes that make use of the ROOT SQL interface. They also use some iostream/sstream functions to build the sql query strings.

The library seems to compile perfectly fine, but when I try and load it, I get the following error:

gSystem->Load(“libDQM.so”);
dlopen error: /net/gamma3/srv/home/wamanda/DQMStudy/./libDQM.so: undefined symbol: __dso_handle
Load Error: Failed to load Dynamic link library /net/gamma3/srv/home/wamanda/DQMStudy/./libDQM.so
*** Interpreter error recovered ***

Does anyone have any idea what is causing this or how I can fix the problem?

The machine is running what I believe is a version of scientific Linux. The compiler is g++ (version 3.4.6). The ROOT version is 5.14.

                                        Amanda
2

Your library libDQM.so depends on other shared libs that should be loaded before libDQM.
Could you do
ldd libdQM.so
to see the list of dependencies?

Rene

3

Thanks—I managed to work out the problem with my paths and loading order, and it works fine now.