Linking ZMQ to a c++ program in my scratch folder

[Vishnu Raj]

I have a ns3 program under scratch/sample/sample.cc which depends on ZMQ. When I try to run the program, I get this error

scratch/sample/sample.cc.6.o: In function `main':
/media/vish/Y/vish/bits/ns3/source/ns-3.28/build/../scratch/sample/sample.cc:54: undefined reference to `zmq_ctx_new'
/media/vish/Y/vish/bits/ns3/source/ns-3.28/build/../scratch/sample/sample.cc:55: undefined reference to `zmq_socket'
/media/vish/Y/vish/bits/ns3/source/ns-3.28/build/../scratch/sample/sample.cc:56: undefined reference to `zmq_connect'
collect2: error: ld returned 1 exit status

Waf: Leaving directory `/media/vish/Y/vish/bits/ns3/source/ns-3.28/build'
Build failed
 -> task in 'sample' failed (exit status 1):
    {task 140042867840272: cxxprogram sample.cc.6.o -> sample}
['/usr/bin/g++', '-lzmq', '-pthread', '-pthread', 'scratch/sample/sample.cc.6.o', '-o', '/media/vish/Y/vish/bits/ns3/source/ns-3.28/build/scratch/sample/sample', '-Wl,-Bstatic', '-Wl,-Bdynamic', '-Wl,--no-as-needed', '-L.', '-lns3.28-aodv-debug', '-lns3.28-test-debug', '-lns3.28-dsr-debug', '-lns3.28-mesh-debug', '-lns3.28-netanim-debug', '-lns3.28-wave-debug', '-lns3.28-wifi-debug', '-lns3.28-lr-wpan-debug', '-lns3.28-lte-debug', '-lns3.28-spectrum-debug', '-lns3.28-antenna-debug', '-lns3.28-applications-debug', '-lns3.28-csma-layout-debug', '-lns3.28-dsdv-debug', '-lns3.28-flow-monitor-debug', '-lns3.28-internet-apps-debug', '-lns3.28-wimax-debug', '-lns3.28-point-to-point-layout-debug', '-lns3.28-nix-vector-routing-debug', '-lns3.28-olsr-debug', '-lns3.28-sixlowpan-debug', '-lns3.28-tap-bridge-debug', '-lns3.28-internet-debug', '-lns3.28-bridge-debug', '-lns3.28-point-to-point-debug', '-lns3.28-mpi-debug', '-lns3.28-traffic-control-debug', '-lns3.28-buildings-debug', '-lns3.28-propagation-debug', '-lns3.28-uan-debug', '-lns3.28-mobility-debug', '-lns3.28-energy-debug', '-lns3.28-config-store-debug', '-lns3.28-csma-debug', '-lns3.28-fd-net-device-debug', '-lns3.28-virtual-net-device-debug', '-lns3.28-topology-read-debug', '-lns3.28-network-debug', '-lns3.28-stats-debug', '-lns3.28-core-debug', '-lrt', '-lgsl', '-lgslcblas', '-lm', '-lsqlite3', '-lgtk-x11-2.0', '-lgdk-x11-2.0', '-lpangocairo-1.0', '-latk-1.0', '-lcairo', '-lgdk_pixbuf-2.0', '-lgio-2.0', '-lpangoft2-1.0', '-lpango-1.0', '-lgobject-2.0', '-lglib-2.0', '-lfontconfig', '-lfreetype', '-lxml2']

Following the discussion from other threads, i have put this in my `ns-3.28/wscript`  :

    have_zmq = conf.check_cfg( package='libzmq', args=['--cflags', '--libs'], uselib_store='ZMQ', mandatory=True)

   conf.env['ENABLE_ZMQ'] = have_zmq

   conf.report_optional_feature("ZMQ", "libzmq", conf.env['ENABLE_ZMQ'], "ZMQ not found")  

    conf.env.append_value('CXXFLAGS', '-DNO_INT_SIZE_CHECK')

   conf.env.append_value('CXXFLAGS', '-Wall')

   conf.env.append_value('CXXFLAGS', '-g')

   conf.env.append_value('CXXFLAGS', '-DNDEBUG')

   conf.env.append_value('CXXFLAGS', '-pipe')                    

    # conf.env.append_value('INCLUDES', '<path_to_include_folder>')

   # conf.env.append_value('LINKFLAGS', '-L<path_to_lib_folder>')

   conf.env.append_value('LINKFLAGS', '-lzmq' )

   # ==========================================================================

How can I solve this problem?

[arshi mohini]

Hi Vishnu,

I am facing similar issue. From what I infer, the issue is not with my linking of ns3 and ZeroMQ. I have attached a screenshot of the error that I am getting. You can see that my program can successfully invoke zmq.hpp from /usr/include path but crashes when it can't find function definitions like 'zmq_errno' `zmq_ctx_new' etc. Please let me know if you were able to resolve the issue and how?

[Tom Henderson]

On 2/12/19 6:05 PM, arshi mohini wrote:
> Hi Vishnu,
>
> I am facing similar issue. From what I infer, the issue is not with my
> linking of ns3 and ZeroMQ. I have attached a screenshot of the error
> that I am getting. You can see that my program can successfully invoke
> zmq.hpp from /usr/include path but crashes when it can't find function
> definitions like 'zmq_errno' `zmq_ctx_new' etc. Please let me know if
> you were able to resolve the issue and how?

Your program is not successfully linking because the libzmq is not found
on your library path.

Can you try finding where the libzmq.so.0 library is located, and then
add that directory to your library path? For instance, if it is in
/usr/local/lib:

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib

and then try again.

- Tom

[Henrique Bastos]

I'm facing this same issue, I can find the CPPZMQ, but it looks like that it's not linked with libzmq.

I was able to use it normally with wscript, but now using cmake and ns3 3.36, it's not working.

/usr/bin/ld: CMakeFiles/scratch_scratch-simulator.dir/scratch-simulator.cc.o: in function `zmq::context_t::close()':
/usr/local/include/zmq.hpp:868: undefined reference to `zmq_ctx_term'
/usr/bin/ld: CMakeFiles/scratch_scratch-simulator.dir/scratch-simulator.cc.o: in function `zmq::error_t::what() const':
/usr/local/include/zmq.hpp:296: undefined reference to `zmq_strerror'
/usr/bin/ld: CMakeFiles/scratch_scratch-simulator.dir/scratch-simulator.cc.o: in function `zmq::error_t::error_t()':
/usr/local/include/zmq.hpp:292: undefined reference to `zmq_errno'
/usr/bin/ld: CMakeFiles/scratch_scratch-simulator.dir/scratch-simulator.cc.o: in function `zmq::context_t::context_t()':
/usr/local/include/zmq.hpp:798: undefined reference to `zmq_ctx_new'

collect2: error: ld returned 1 exit status

gmake[2]: *** [scratch/CMakeFiles/scratch_scratch-simulator.dir/build.make:103: /home/fhb/5glena_v2x/ns-3-dev/build/scratch/ns3-dev-scratch-simulator-default] Error 1
gmake[1]: *** [CMakeFiles/Makefile2:16926: scratch/CMakeFiles/scratch_scratch-simulator.dir/all] Error 2
gmake: *** [Makefile:146: all] Error 2
Finished executing the following commands:
cd cmake-cache; cmake --build . -j 11 ; cd ..

[Gabriel Ferreira]

What isn't working? You don't even seem to be linking zmq to the scratches. 

Add the following to the CMakeLists.txt in the scratch directory.

find_library(ZMQ zmq)

link_libraries(${ZMQ})

[Henrique Bastos]

Thanks, Gabriel!!!

Now it is working. I was adding it to the main CMakeLists.txt and not inside the scratch folder.

[djab _eR]

where can i find the main CMakeLists.txt for ndnsim ?