Thread: Socket select() method troubles

So, I have a small program that I am trying to get up and running. I must tell you all that I've not programmed in C++ for a while. So, please be gentle. Attached is code that I've put in place for the client-side of my program. All I want this code to do is connect to the socket specified and deliver a bit string every 5 seconds. And if it receives a message from the server; to output a message (just to indicate that it is being executed). However, this is not working ....

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Code:

#include <sys/socket.h>       
#include <sys/types.h>        
#include <arpa/inet.h>        
#include <unistd.h>           
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <iostream>
#include "helper.h"
using namespace std;

#define MAXDATASIZE 100

int main(int argc, char *argv[]) {
    int sockfd, max, num_bytes, rv;
        short int port;
        char* endptr;
        struct sockaddr_in servaddr;
        char buf[MAXDATASIZE];
        struct timeval tv;
            fd_set readfds;


            tv.tv_sec = 5;
            tv.tv_usec = 0;


        port = strtol(argv[1], &endptr, 0);
        sockfd = socket(AF_INET, SOCK_STREAM, 0);

        bzero(&servaddr, sizeof(servaddr));
        servaddr.sin_family = AF_INET;
        servaddr.sin_port = htons(port);
        inet_pton(AF_INET, argv[2], &servaddr.sin_addr);

        connect(sockfd, (sockaddr*) &servaddr, sizeof(servaddr));

        cout << "Connected..." << endl;

        FD_ZERO(&readfds);
        FD_SET(sockfd, &readfds);

        // Set the max fd
        max = sockfd;

        do {
                rv = select(max+1, &readfds, NULL, NULL, &tv);

                printf("After select(): %d\n", rv);


        if (rv == -1) {
            perror("select");
        }
        else if (rv == 0) {
            // We timed out.  That means no input .. 
                                    // Generate a BitString packet
                        BitstringPacket data_packet =                   generate_bitstring_packet();
        
                        // Send the BitString Packet to the server
                        if (send(sockfd, &data_packet, sizeof(data_packet), 0) == -1) {
                                perror("recv");
                                exit(1);
                        }
      }
      else if ( FD_ISSET(sockfd, &readfds) ) {        
          printf("Received something\n");
      }
      else {
          printf("What is going on?");
      }

    } while(1);

    close(sockfd);
    exit(0);
}

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It has no problems sending the bitstrings, but it does not ever receive a message from the server, which it should because I've validated the message being sent. I am sure that I am doing something _stupid_ here. Please let me know, gently ;-)