/* Client program for Internet TCP sockets */
/* Client assumes that the server has  */
/* IP addr = 194.27.78.02   and port = 7000 */


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

#define PORT  7000 /* Port of the server */
#define SIZE sizeof(struct sockaddr_in)

int
main(void)
{
    char buf[1024];
    int n, s, ns, len;

    /* For client's address, OS will assign IP of this host  */
    /* and arbitrary port number: */
    struct sockaddr_in cli = {AF_INET, INADDR_ANY, INADDR_ANY};

    /* For server's address */
    struct sockaddr_in srv = {AF_INET, PORT, inet_addr("194.27.78.02")}; 
    /* Or in the following way (IP addr could be assigned later): */
    /* struct sockaddr_in srv = {AF_INET, PORT}; */
     
    printf("TCP CLIENT: starting ...\n");

    /* Convert and store IP address of the server: 194.27.78.02 (helium) */
    /* if this is not done in initialisation of srv structure above */ 
    /* srv.sin_addr.s_addr = inet_addr("194.27.78.02"); */

    /*
     * Create the Internet socket, of SOCK_STREAM type.
     */
    if ((s = socket(AF_INET, SOCK_STREAM, 0)) < 0) 
        {
        perror("socket problem");
        exit(1);
        }



    /*
     * Bind the socket to the IP address of this host.
     */
    if (bind(s, (struct sockaddr *) &cli, SIZE) < 0) 
        {
        perror("bind problem");
        exit(1);
        }

    /* Try to establish a connection with the server */
    
    len = SIZE;
    if (connect(s, (struct sockaddr *)&srv, len) < 0)
    {perror("connect problem"); exit(1);}

    /*
     * Send a message to the server via socket s
     */
    n = send(s, "This is a request from client\n", 30, 0);
    if (n < 0) {perror("send problem"); exit(1);}

    
    printf ("TCP CLIENT: a request is sent ...\n");
    
    /* Receiving and printing a reply from server */

    n = recv(s, buf, sizeof(buf), 0);
    write (1, buf, n);
    /*
     * Close the socket and terminate.
     */

    close(s);
    printf ("TCP CLIENT terminated...\n");
    exit(0);
}