MSYS 下winsocket 简单使用

• server.cpp

  #include <iostream> 
  #include <winsock2.h>  
  
  using namespace std;
  
  int main(int argc, char* argv[])
  {    
    //初始化WSA  
    WORD sockVersion = MAKEWORD(2, 2);
    WSADATA wsaData;
    if (WSAStartup(sockVersion, &wsaData) != 0)
    {
      return 0;
    }
  
    //创建套接字  
    SOCKET slisten = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (slisten == INVALID_SOCKET)
    {
      cout << "create socket error !" << endl;
      return 0;
    }
  
    //绑定IP和端口  
    sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(8888);
    sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
  
    if (bind(slisten, (LPSOCKADDR)&sin, sizeof(sin)) == SOCKET_ERROR)
    {
      cout << "bind error !" << endl;
      return 0;
    }
  
    //开始监听  
    if (listen(slisten, 5) == SOCKET_ERROR)
    {
      cout << "listen error !" << endl;
      return 0;
    }
  
    //循环接收数据  
    SOCKET sClient;
    sockaddr_in remoteAddr;
    int nAddrlen = sizeof(remoteAddr);
    char revData[255];
    while (true)
    {
      cout << "wait connect..." << endl;
      sClient = accept(slisten, (SOCKADDR *)&remoteAddr, &nAddrlen);
      if (sClient == INVALID_SOCKET)
      {
        cout << "accept error !" << endl;
        continue;
      }
  
      cout << "accept a connect!" << inet_ntoa(remoteAddr.sin_addr) << endl;
  
      //接收数据  
      int ret = recv(sClient, revData, 255, 0);
      if (ret > 0)
      {
        revData[ret] = 0x00;
        cout << revData << endl;
      }
  
      //发送数据  
      const char * sendData = "hello client\n";
      send(sClient, sendData, strlen(sendData), 0);
      closesocket(sClient);
    }
  
    closesocket(slisten);
    WSACleanup();
    return 0;
  }
  

• client.cpp

  #include<winsock2.h>
  #include<iostream>
  #include<string>
  
  using namespace std;
  #pragma comment(lib, "ws2_32.lib")
  
  int main()
  {
    WORD sockVersion = MAKEWORD(2, 2);
    WSADATA data;
    if (WSAStartup(sockVersion, &data) != 0)
    {
      return 0;
    }
  
    while (true) 
    {
      SOCKET sclient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
      if (sclient == INVALID_SOCKET)
      {
        cout << "invalid socket!" << endl;
        return 0;
      }
  
      sockaddr_in serAddr;
      serAddr.sin_family = AF_INET;
      serAddr.sin_port = htons(8888);
      serAddr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
      if (connect(sclient, (sockaddr *)&serAddr, sizeof(serAddr)) == SOCKET_ERROR)
      {  
        //连接失败 
        cout << "connect error !" << endl;
        closesocket(sclient);
        return 0;
      }
  
      string data;
      cin >> data;
      const char * sendData;
      sendData = data.c_str();   //string转const char* 
                    
      /*
      send()用来将数据由指定的socket传给对方主机
      int send(int s, const void * msg, int len, unsigned int flags)
          s为已建立好连接的socket，msg指向数据内容，len则为数据长度，参数flags一般设0
          成功则返回实际传送出去的字符数，失败返回-1，错误原因存于error
      */
      send(sclient, sendData, strlen(sendData), 0);
      
      char recData[255];
      int ret = recv(sclient, recData, 255, 0);
      if (ret>0)
      {
        recData[ret] = 0x00;
        cout << recData << endl;
      }
      closesocket(sclient);
    }
  
    WSACleanup();
  
    system("pause");
    return 0;
  }
  

• makefile

  lib := -lwsock32
  
  all: server client
  
  server:
    g++ server.cpp -o server.exe ${lib}
  
  
  client:
    g++ client.cpp -o client.exe ${lib}
  
  clean:
    rm *.exe
  

udp 客户端测试

#include <stdio.h>
#include<winsock2.h>

#pragma comment(lib, "ws2_32.lib")

int main(int argc, char const *argv[])
{
    /* 初始化套接字动态库 */
    WSADATA data;
    if (WSAStartup(MAKEWORD(2, 2), &data) != 0)
    {
        printf("WSAStartup error\n");
        return -1;
    }

    /* 创建网络套接字 */
    SOCKET sclient = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
    if (sclient == INVALID_SOCKET)
    {
      printf("invalid socket!");
      return 0;
    }

    /* 设置服务器地址信息  */
    struct sockaddr_in serv_addr;
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(8888);
    serv_addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");

    int serv_addr_len = sizeof(serv_addr);

    while (1)
    {
        int ch = getchar();
        
        char buf[512];
        int n = 0;

        /* 接收数据 */
        if (ch == 'R' || ch == 'W')
        {
again:
            n = recvfrom(sclient, buf, 512 - 1, 0, (struct sockaddr *)&serv_addr, &serv_addr_len);
            
            if(n < 0)
            {
                printf("recv error\n");
                goto err;
            }
            buf[n] = '\0';
            printf("recv %d bytes: %s\n", n, buf);

            /* 循环接收 */
            if(ch == 'W')
            {
                goto again;
            }
        }

        /* 发送数据 */
        else if (ch == 'S')
        {
            n = sendto(sclient, "Hello", 6, 0, (struct sockaddr *)&serv_addr, serv_addr_len);

            if (n < 0)
            {
                printf("sendto error\n");
                goto err;
            }
            
        }

        /* 退出测试 */
        else if(ch == 'E')
        {
            break;
        }
    }

err:
    closesocket(sclient);
    WSACleanup();
    
    return 0;
}