#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>

#define MAXDATASIZE 16

int main(int argc, char *argv[])
{
        int numbytes, sockfd, sockbytes, i, answer, x=0;
        char buf[MAXDATASIZE], buf2[1024];
        struct hostent *he;
        struct sockaddr_in their_addr; // connector's address information

        if (argc != 2) {
            fprintf(stderr,"usage: client hostname\n");
            exit(1);
        }

        if ((he=gethostbyname(argv[1])) == NULL) {  // get the host info
            perror("gethostbyname");
            exit(1);
        }

        if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
            perror("socket");
            exit(1);
        }

        their_addr.sin_family = AF_INET;    // host byte order
        their_addr.sin_port = htons(5842);  // short, network byte order
        their_addr.sin_addr = *((struct in_addr *)he->h_addr);
        memset(their_addr.sin_zero, '\0', sizeof their_addr.sin_zero);

        if (connect(sockfd, (struct sockaddr *)&their_addr, sizeof(struct sockaddr)) == -1) {
            perror("connect");
            exit(1);
        }

        if ((numbytes=recv(sockfd, buf, MAXDATASIZE-1, 0)) == -1) {
            perror("recv");
            exit(1);
        }
      buf[numbytes] = '\0';

        for(i=0;i<numbytes;i++) printf("Received: %d\n",buf[i]);
        for(i=0;i<numbytes;i++) answer+=buf[i];

        printf("answer is %d\n", answer);


        if (send(sockfd, &answer, sizeof(unsigned long), 0) == -1)
                perror("send");

while(x<4) {
        if ((numbytes=recv(sockfd, buf2, 1023, 0)) == -1) {
            perror("recv");
            exit(1);
        }

        printf("%s\n", buf2);
x++;
}

        close(sockfd);

        return 0;
}


=============

returns:

# ./client vortex.labs.pulltheplug.org
Received: 166
Received: 124
Received: 53
Received: 1
answer is 344
ñÑIB2n
bzzzt, wrong

bzzzt, wrong

bzzzt, wrong