/*
 * a stream socket client demo
 */

#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 PORT 1234               // the port client will be connecting to 
#define MAXDATASIZE 100 // max number of bytes we can get at once 


int
main(int argc, char **argv)
{
        int sockfd;
        char buffer[MAXDATASIZE];
        short int port = PORT;
        struct hostent *he;
        struct sockaddr_in their_addr;
                // connector's address information 

        if (argc < 2) {
                fprintf(stderr,"usage: tcp_client <hostname> [port]\n");
                exit(1);
        }

        if (argc == 3)
                port = atoi(argv[2]);

        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);
        }

        memset(&their_addr, 0, sizeof(their_addr));
        their_addr.sin_family = AF_INET;
        their_addr.sin_port = htons(port);
        their_addr.sin_addr = *((struct in_addr *)he->h_addr);

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

        if (!fork()) {
                int numBytes;

                while (1) {
                        // child process
                        if ((numBytes = recv(sockfd, buffer, sizeof(buffer) - 1, 0)) == -1) {
                                perror("recv");
                                sleep(1);
                                // want the read thread to stay alive
                                continue;
                        }

                        buffer[numBytes] = '\0';
                        printf("%s", buffer);
                }
        } else {
                while (1) {
                        // parent process
                        if (fgets(buffer, sizeof(buffer) - 1, stdin) == NULL) {
                                perror("fgets");
                                exit(1);
                        }

                        if ((send(sockfd, buffer, strlen(buffer), 0)) == -1) {
                                perror("send");
                                exit(1);
                        }
                }
        }

        close(sockfd);

        return 0;
}