#include <stdio.h>
#include <string.h>

#include <winsock2.h>  
#define PORT 8888
#define SERVER_IP "127.0.0.1"
#define  BUFFER_SIZE 4196

const char* kExitFlag = "exit";

int main() {
	// 初始化socket dll。
	WORD winsock_version = MAKEWORD(2,2);
	WSADATA wsa_data;
	if (WSAStartup(winsock_version, &wsa_data) != 0) {
		printf("Failed to init socket!\n");
		return 1;
	}
	
	SOCKET client_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (client_socket == INVALID_SOCKET) {
		printf("Failed to create server socket!\n");
		return 2;
	}
	
	sockaddr_in server_addr;
	server_addr.sin_family = AF_INET;
	server_addr.sin_port = htons(PORT);
	server_addr.sin_addr.S_un.S_addr = inet_addr(SERVER_IP);
	if (connect(client_socket, (LPSOCKADDR)&server_addr, sizeof(server_addr)) == SOCKET_ERROR) {
		printf("Failed to connect server: %ld !\n", GetLastError());
		return 3;
	}
	
	char recv_data[BUFFER_SIZE+1];
	
	while (true) {
		char data[BUFFER_SIZE+1];
		printf("Input data: ");
		scanf("%s",data);
		if (send(client_socket, data, strlen(data), 0) < 0) {
			printf("Failed to send data!\n");
			break;
		}
		
		int ret = recv(client_socket, recv_data, BUFFER_SIZE, 0);
		if (ret < 0) {
			printf("Failed to receive data!\n");
			break;
		}
		recv_data[ret]=0; // correctly ends received string
		
		printf("Receive data from server: \"%s\"\n",recv_data);
		
		if (data == kExitFlag) {
			printf("Exit!\n");
			break;
		}
	}
	
	closesocket(client_socket);
	WSACleanup();
	
	return 0;
}