Re: How to send a uint8_t through a socket

Hi,
Here is the code.The value of b in the struc is going through but not
a .when i print it in the server side..nothing is getting printed.
I changed the code a little[from the first post so htons/ntonl is
used]

struct exam
{
uint8_t b;
uint32_t a;
};

////////////////////////////////////server

int main()
{
  int listenSocket, connectSocket, i;
  unsigned short int listenPort;
  socklen_t clientAddressLength;
  struct sockaddr_in clientAddress, serverAddress;
  char line[LINE_ARRAY_SIZE];

  cout << "Enter port number to listen on (between 1500 and 65000): ";
  cin >> listenPort;

  // Create socket for listening for client connection requests.
  listenSocket = socket(AF_INET, SOCK_STREAM, 0);
  if (listenSocket < 0) {
    cerr << "cannot create listen socket";
    exit(1);
  }

  serverAddress.sin_family = AF_INET;
  serverAddress.sin_addr.s_addr = htonl(INADDR_ANY);
  serverAddress.sin_port = htons(listenPort);

  if (bind(listenSocket,
           (struct sockaddr *) &serverAddress,
           sizeof(serverAddress)) < 0) {
    cerr << "cannot bind socket";
    exit(1);
  }
`
  // Wait for connections from clients.
    listen(listenSocket, 5);

  while (1) {
    cout << "Waiting for TCP connection on port " << listenPort <<
" ...\n";

    clientAddressLength = sizeof(clientAddress);
    connectSocket = accept(listenSocket,
                           (struct sockaddr *) &clientAddress,
                           &clientAddressLength);
    if (connectSocket < 0) {
      cerr << "cannot accept connection ";
      exit(1);
    }

    // Show the IP address of the client.
      cout << " connected to " << inet_ntoa(clientAddress.sin_addr);

     char x[123];
     exam *o;
while (recv(connectSocket,x,sizeof(exam), 0) > 0) {

    cout <<((exam *)x)->a<<"\n";
    cout <<((exam *)x)->b<<"\n";
  }
}

////////////////////client

int main()
{
  int socketDescriptor;
  unsigned short int serverPort;
  struct sockaddr_in serverAddress;
  struct hostent *hostInfo;
  char buf[MAX_LINE + 1], c;
  uint8_t flag=3;
    buf[0]=flag;

cout << "Enter server host name or IP address: ";
  cin.get(buf, MAX_LINE, '\n');

  hostInfo = gethostbyname(buf);
  if (hostInfo == NULL) {
    cout << "problem interpreting host: " << buf << "\n";
    exit(1);
  }

  cout << "Enter server port number: ";
  cin >> serverPort;
  cin.get(c); // dispose of the newline

   socketDescriptor = socket(AF_INET, SOCK_STREAM, 0);
  if (socketDescriptor < 0) {
    cerr << "cannot create socket\n";
    exit(1);
  }

  serverAddress.sin_family = hostInfo->h_addrtype;
  memcpy((char *) &serverAddress.sin_addr.s_addr,
         hostInfo->h_addr_list[0], hostInfo->h_length);
  serverAddress.sin_port = htons(serverPort);

  if (connect(socketDescriptor,
              (struct sockaddr *) &serverAddress,
              sizeof(serverAddress)) < 0) {
    cerr << "cannot connect\n";
    exit(1);
  }

exam *t1,t2;
t1=&t2;;
t2.a=21;

t2.b=1;

unsigned char x[10];
char *y=(char *)&t2;

 // Stop when the user inputs a line with just a dot.

    // Send the line to the server.
    if (send(socketDescriptor,y,sizeof(exam), 0) < 0) {
     cerr << "cannot send data ";
     close(socketDescriptor);
     exit(1);
     }

      }

      return 0;

}