从Network C ++接收数据

Question

I have a python function to send data over the network by data gram socket.In the receiver end i have to use c++ to receive that data But the receiver can't receive any meaningful data.What should be used to get the string in the exact format it was sent?

Python code

def send(self, command):
        segments = command.split() # split command on spaces
        if len(segments) < 5 or segments[1] not in self.hosts or segments[2] not in self.hosts: # sanity check
            print('invalid arguments')
            return
        else:
            h1 = map(int, segments[1].split('.'))# segment 1 contains a IP address
            h2 = map(int, segments[2].split('.'))# segment 2 contains an IP address
            fmt = '4s4B4Bh' + segments[3] + 's'# segemt 3 is string length segment 4 is a string
            buf = struct.pack(fmt, segments[0], h1[0], h1[1], h1[2], h1[3], h2[0], h2[1], h2[2], h2[3], int(segments[3]), ' '.join(segments[4:]))
            print('sending to {0}'.format(segments[1])) # print a message before sending to source
            self.s.sendto(buf, (segments[1], self.port)) # send to source
            #self.s.sendto(command, (segments[1], self.port)) # send to source

C++ code

bytes_received = recvfrom(sockfd, buffer, sizeof(buffer), 0, (struct sockaddr*) &client_address, &addrlen);
        //print(buffer);
        if(bytes_received==-1)
        {
            perror("recvfrom");
            printf("error %s\n",strerror(errno));
        }

        printf("[%s:%hu]: %s \n", inet_ntoa(client_address.sin_addr), ntohs(client_address.sin_port), buffer);

All the sockets are created properly

Answer 1

If you receive something like "send ???????" I'd expect encoding problems during sending. '?' is 0x3F (dec 63) which usually comes from characters out of basic ASCII (less then 127) table. I'm not familiar with python, but can you ensure you use proper (eg UTF-8, for sure not UTF-16/32 and perhaps not ASCII) encoding while transforming python string into byte array?