win32 | WinSock2網路程式設計 | socket-tcp通訊

阿新 • • 發佈：2020-12-02

今天覆習了一下tcp通訊的實現，寫了寫程式碼。

簡單的總結一下：

伺服器作為監聽者的角色需要先建立伺服器socket套接字，然後使用bind繫結套接字和埠資訊等等，再建立用於連線客戶端的socket套接字，使用accept函式等待客戶端的連線並處理。

客戶端則只需要建立用於連線伺服器的socket套接字connect函式建立與遠端主機的連結就可以了。

同時需要注意的是錯誤的處理和關閉套接字等等。

伺服器：

  1 #include<WinSock2.h>
  2 #pragma comment(lib,"ws2_32.lib")
  3 #include <stdio.h>
  4 
 #include <string.h>
  5 
  6 
  7 
  8 int main(){
  9     WSADATA wsaData;   // 初始化返回資訊結構體
 10     WORD wVersion = MAKEWORD(2,2); // 製作版本號
 11     SOCKET hServer;       // 定義套接字控制代碼
 12     if (WSAStartup(wVersion, &wsaData)){       //初始化
 13         printf("initial failed");
 14         return 0;
 
 15     }
 16     //in_addr addr; // ip地址結構體
 17     //addr.s_addr = inet_addr("127.0.0.1"); // 轉化字串為32位整形ip地址
 18     //char* lpszIp = inet_ntoa(addr);  //整形轉化為字串形式
 19     
 20     hServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); //tcp形式流式套接字
 21     if (hServer == INVALID_SOCKET){
 22         printf("socket failed \n 
");
 23     }
 24     sockaddr_in addrServer;
 25     addrServer.sin_family = AF_INET;
 26     addrServer.sin_port = htons(8888);     // 指定埠
 27     addrServer.sin_addr.s_addr = htonl(INADDR_ANY);  //指定能訪問的ip
 28     int nRet = bind(hServer, (sockaddr*)&addrServer, sizeof(addrServer));
 29     if (nRet == SOCKET_ERROR){
 30         printf("bind error \n");
 31         closesocket(hServer);
 32         WSACleanup();
 33         return 0;
 34     }
 35     //進行監聽
 36     nRet = listen(hServer,5);       //最多監聽5個
 37     printf("start listening ... \n");
 38     if (nRet == SOCKET_ERROR){
 39         printf("listen error \n");
 40         closesocket(hServer);
 41         WSACleanup();
 42         return 0;
 43     }
 44     
 45     //接收客戶端請求
 46     SOCKET hClient;
 47     sockaddr_in addrClient;
 48     int nLen = sizeof(addrClient);
 49     hClient = accept(hServer,(sockaddr *)&addrClient, &nLen); // ?建立監聽控制代碼,直到接收到請求
 50     if (hClient == INVALID_SOCKET){
 51         printf("accept error \n");
 52         closesocket(hServer);
 53         WSACleanup();
 54         return 0;
 55     }
 56     printf("Get a connect! \n");
 57     send(hClient, "helllllllooooooo!!!!!!",sizeof("helllllllooooooo!!!!!!"), 0);
 58 
 59     char szBuf[255];
 60     //迴圈接收客戶端資料
 61     while (1)
 62     {
 63         memset(szBuf, 0, sizeof(szBuf)); // 清空緩衝區
 64         nRet = recv(hClient, szBuf,sizeof(szBuf),0);
 65         if (nRet == SOCKET_ERROR){
 66             printf("recv error \n");
 67             closesocket(hClient);
 68             closesocket(hServer);
 69             WSACleanup();
 70             return 0;
 71         }
 72         
 73         char sPrint[sizeof(szBuf)];
 74         sprintf(sPrint, "IP:%s, recv msg: %s ",inet_ntoa(addrClient.sin_addr),szBuf);//格式化字串
 75         printf(sPrint);
 76         if(strcmp(szBuf, "close") == 0){ // 檢測退出
 77             nRet = send(hClient,"close",strlen("close"), 0);
 78             break;
 79         }
 80         else{
 81             //接收到資料
 82             sprintf(sPrint, "the server has recved your msg: %s ", szBuf);
 83             nRet = send(hClient,sPrint,strlen(sPrint), 0);
 84             if (nRet == SOCKET_ERROR){
 85                 printf("send err \n");
 86                 closesocket(hClient);
 87                 closesocket(hServer);
 88                 WSACleanup();
 89                 return 0;
 90             }
 91         }
 92         
 93         
 94     }
 95     closesocket(hClient);
 96     closesocket(hServer);
 97     WSACleanup();
 98     
 99     return 0;
100 }

客戶端：

 1 #include<WinSock2.h>
 2 #pragma comment(lib,"ws2_32.lib")
 3 #include <stdio.h>
 4 #include <string.h>
 5 
 6 
 7 
 8 int main(){
 9     WSADATA wsaData;   // 初始化返回資訊結構體
10     WORD wVersion = MAKEWORD(2,2); // 製作版本號
11     SOCKET hClient;       // 定義套接字控制代碼
12     if (WSAStartup(wVersion, &wsaData)){       //初始化
13         printf("initial failed");
14         return 0;
15     }
16 
17     hClient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); //tcp形式流式套接字
18     if (hClient == INVALID_SOCKET){
19         printf("socket failed \n");
20     }
21 
22     sockaddr_in addrServer;
23     addrServer.sin_family = AF_INET;
24     addrServer.sin_port = htons(8888);     // 指定埠
25     addrServer.sin_addr.s_addr = inet_addr("192.168.56.101");               //指定要連線的ip
26     //建立連線
27     int nRet = connect(hClient,(sockaddr*)&addrServer, sizeof(addrServer));
28     if (nRet == SOCKET_ERROR){
29         printf("connect error \n");
30         closesocket(hClient);
31         WSACleanup();
32         return 0;
33     }
34     printf("connect successsssss!!!\n");
35 
36     char szBuf[255];
37     //迴圈接收客戶端資料
38     while (1)
39     {
40         memset(szBuf, 0, sizeof(szBuf)); // 清空緩衝區
41         nRet = recv(hClient, szBuf,sizeof(szBuf),0);
42         if (nRet == SOCKET_ERROR){
43             printf("recv error \n");
44             closesocket(hClient);
45             WSACleanup();
46             return 0;
47         }
48         
49         char sPrint[sizeof(szBuf)];
50         sprintf(sPrint, "recv msg: %s ",szBuf);//格式化字串
51         printf(sPrint);
52         if(strcmp(szBuf, "close") == 0){ // 檢測退出
53             nRet = send(hClient,"close",strlen("close"), 0);
54             break;
55         }
56         else{
57             //接收到資料
58             if (strcmp(szBuf, "helllllllooooooo!!!!!!") == 0){
59                 send(hClient, "wow", sizeof("wow"),0);
60             }
61         }
62         
63         
64     }
65     closesocket(hClient);
66     WSACleanup();
67     
68     return 0;
69 }