Question

I am trying to send a proto over a socket, but i am getting segmentation error. Could someone please help and tell me what is wrong with this example?

file.proto

message data{  
    required string x1 = 1;
    required uint32 x2 = 2;
    required float x3 = 3;
}

xxx.cpp

    ...
    data data_snd, data_rec;

    //sending data to the server
    if (send(socket, &data_snd, sizeof(data_snd), 0) < 0) {
       cerr << "send() failed" ;
       exit(1);
     }  

     //receiving data from the client
     if (recv(socket, &data_rec, sizeof(data_rec), 0) < 0) {
        cerr << "recv() failed";
        exit(1);
     }  

Thanks for help and replies-

Answer 1

You’re not supposed to write the protobuf object itself to the socket. Use the SerializeXXX family of methods to get a sequence of bytes which you can write to the socket.

std::string buf;
data.SerializeToString(&buf);
// now you can write buf.data() to the socket