1 #include<winsock2.h>//winsock的头文件
 2 #include<iostream>
 3  
 4 using  namespace  std;
 5 
 6 //指定动态库的lib文件
 7 #pragma comment(lib,"ws2_32.lib")

 9 //TCP客户端
10 int main()
11 {
12 
13     //初始化winsock2.2相关的动态库
14     WSADATA  wd;//获取socket相关信息
15     if (WSAStartup(MAKEWORD(2, 2), &wd) != 0)//0表示成功
16     {
17         cout << "WSAStartup  error:" << WSAGetLastError() << endl;
18         return 0;
19     }
20 
21 
22     //1.创建TCP   socket , 流式套接字
23     SOCKET   s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
24     if (s == INVALID_SOCKET)
25     {
26         cout << "socket  error:" << WSAGetLastError() << endl;
27         return 0;
28     }
29 
30     //2.链接服务端
31     sockaddr_in   addr;//不建议使用sockaddr，建议用sockaddr_in
32     addr.sin_port = htons(6000);//网络字节序
33     addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");//网络字节序  
34     addr.sin_family = AF_INET; //地址族
35     int len = sizeof(sockaddr_in);
36 
37     if (connect(s, (sockaddr*)&addr, len) == SOCKET_ERROR)
38     {
39         cout << "connect  error:" << WSAGetLastError() << endl;
40         return 0;
41     }
42 
43     //3.接受发送消息
44     int  ret = 0;
45     do
46     {
47         //接受客户端的消息
48         char buf[64] = { '\0' };
49         ret = recv(s, buf, 64, 0);//把flag置0
50         cout << "recv" << inet_ntoa(addr.sin_addr) << ":    " << buf << endl;// inet_ntoa转换为IP字符串
51 
52         //发送
53         ret = send(s, "I am Client!", strlen("I am Client!"), 0);
54 
55         Sleep(1000);
56     } while (ret != SOCKET_ERROR && ret != 0);
57 
58 
59     //4.关闭套接字
60     closesocket(s);
61 
62     //清理winsock环境
63     WSACleanup();
64 
65 
66     return   0;
67 }

注意报错处理方式：

https://blog.csdn.net/u010257002/article/details/45393463