/* ** tcp_client.c -- a simple tcp client */ #include #include #include #include #include #include #include #include #include #define PORT 3490 // the port client will be connecting to #define MAXBUFLEN 256 // max number of bytes we can get at once int main(int argc, char *argv[]) { int sockfd, numbytes; char buf[MAXBUFLEN]; struct hostent *he; struct sockaddr_in their_addr; // connector's address information if (argc != 2) { fprintf(stderr,"usage: tcp_client hostname\n"); exit(1); } if ((he=gethostbyname(argv[1])) == NULL) { // get the host info perror("gethostbyname"); exit(1); } // create a tcp socket if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) { perror("socket"); exit(1); } // fill in server info their_addr.sin_family = AF_INET; // host byte order their_addr.sin_port = htons(PORT); // 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); // make a tcp connection to the server if (connect(sockfd, (struct sockaddr *)&their_addr, sizeof their_addr) == -1) { perror("connect"); exit(1); } // receive data from the server if ((numbytes=recv(sockfd, buf, MAXBUFLEN-1, 0)) == -1) { perror("recv"); exit(1); } buf[numbytes] = '\0'; printf("Received: %s",buf); close(sockfd); return 0; }