I call:

bitcoind -zmqpubrawtx=ipc:///tmp/bitcoind.tx.raw

or even call:

bitcoind -zmqpubhashtx=tcp://127.0.0.1:9050 - zmqpubrawtx=ipc:///tmp/bitcoind.tx.raw

where 9050 is port from bicoin config. File /tmp/bitcoind.tx.raw is empty i has lenght=0 How can I dump transactions? I read, this file is websocket and I must subscribe to it:

Client side, then, the ZeroMQ subscriber socket must have the ZMQ_SUBSCRIBE 
option set to one or either of these prefixes (for instance, just hash); 
without doing so will result in no messages arriving. Please see 
contrib/zmq/zmq_sub.py for a working example."

How can I read it programically? I try create c++ program from Python sources and https://github.com/plq/zmq.git

include

#include <iostream>
#include <cstdlib>
#include <cstring>

#include "zmq.hpp"

using std::cout;
using std::endl;

void recv_multipart(zmq::socket_t &socket) {
    int64_t more=-1;
    size_t more_size = sizeof (more);
    while(more) {
        zmq::message_t response;
        socket.recv(&response);

        std::string response_str((const char *)response.data(),
                                                             response.size());
        cout << response_str << endl;

        socket.getsockopt(ZMQ_RCVMORE, &more, &more_size);
    }
}


int main(int argc, char **argv) {
    zmq::context_t context(1);
    zmq::socket_t socket(context, ZMQ_SUB);
    socket.setsockopt(ZMQ_SUBSCRIBE, "hashblock");
    socket.setsockopt(ZMQ_SUBSCRIBE, "hashtx");
    socket.setsockopt(ZMQ_SUBSCRIBE, "rawblock");
    socket.setsockopt(ZMQ_SUBSCRIBE, "rawtx");
    //socket.connect(/*argv[2]*/"ipc:///tmp/bitcoind.tx.raw");
    socket.connect("tcp://127.0.0.1:28332");

    size_t arg_len= std::strlen("Unknown");
    zmq::message_t message(arg_len);
    std::memcpy(message.data(), "Unknown", arg_len);
    socket.send(message);        
    recv_multipart(socket);        
    return 0;
}