/********************************************************************
 * client.c
 *
 *  CLIENT CODE 
 *
 * from https://www.programminglogic.com/
 *      example-of-client-server-program-in-c-using-sockets-and-tcp/
 * 
 * ... with various minor modifications by Jim Mahoney on Nov 2018.
 *********************************************************************/

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

/* Pick a port to use for this client/server connection.
   The server needs to use also use this same port.
   It's an arbitrary number between 1024 and 65535 (16 bit unsigned). */
/* The low ports are reserved for system use; google "port numbers". */
#define PORT 7891

#define BUFFER_SIZE 1024

/* host where server is running : localhost. */
#define HOST "127.0.0.1"

/* shannon.marlboro.college */
#define SHANNON "96.126.107.158"

int main(){
  char buffer[BUFFER_SIZE];
  int connect_socket;
  struct sockaddr_in address;
  socklen_t address_size = sizeof(struct sockaddr_in);

  /*---- Create the socket. The three arguments are: ----
    1) Internet domain 
    2) Stream socket 
    3) Default protocol (TCP in this case)  */      
   connect_socket = socket(PF_INET, SOCK_STREAM, 0);

  /*---- Configure settings of the address struct ----*/
  /* ... which specifies what we want to connect to. */
   
  /* Address family = Internet */
  address.sin_family = AF_INET;
  
  /* Set port number, using htons function to use proper byte order */
  address.sin_port = htons(PORT);

  /* Set IP address to localhost */
  /* address.sin_addr.s_addr = inet_addr(HOST); */
  /* ... or shannon.marlboro.college */
  address.sin_addr.s_addr = inet_addr(SHANNON);

  
  /* Set all bits of the padding field to 0 */
  memset(address.sin_zero, '\0', sizeof(address.sin_zero));

  /*---- Connect the socket to the server using the address struct ----*/
  /* See e.g. http://manpages.ubuntu.com/manpages/bionic/man2/connect.2.html */
  connect(connect_socket, (struct sockaddr *) &address, address_size);
  printf("Client: connection established.\n");

  /*---- Read the message from the server into the buffer ----*/
  recv(connect_socket, buffer, BUFFER_SIZE, 0);

  /*---- Print the received message ----*/
  printf("Client: received: \"%s\"\n", buffer);

  printf("Client exiting.\n");
  close(connect_socket);
  return 0;
}