UDP HelloWord

Client.cpp

#include <stdio.h>
#include <winsock2.h>
#pragma comment (lib,"ws2_32")

//注释的为UDP的代码，方便对比
//流程
//TCP：WSAStarup socket connect recv/send closesocket WSACleanup
int main(int argc,char* argv[])
{
     WSADATA wsaData;
     WSAStartup(MAKEWORD(2,2),&wsaData);

     //SOCKET s = socket(PF_INET,SOCK_STREAM,IPPROTO_TCP);
     SOCKET s = socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP);
    
     sockaddr_in addr;
     addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
     addr.sin_family = PF_INET;
     addr.sin_port = htons(827);

     //connect(s,(SOCKADDR*)&addr,sizeof(SOCKADDR));
     sendto(s,"hello world server UDP",strlen("hello world server UDP") + sizeof(char),
                    0,(SOCKADDR*)&addr,sizeof(SOCKADDR));

     sockaddr_in clientAddrUDP;
    char szBuffer[MAXBYTE] = {0};
     int len = sizeof(SOCKADDR);

     //recv(s,szBuffer,MAXBYTE,NULL);
     recvfrom(s,szBuffer,MAXBYTE,0,(SOCKADDR*)&clientAddrUDP,&len);

     printf("szBuffer = %s \r\n",szBuffer);

     closesocket(s);

     WSACleanup();

     return 0;
}

Server.cpp

//注释的为UDP的代码，方便对比
//TCP::WSAStartup socket bind listen accept send/recv closesocket WSACleanup
#include <winsock2.h>
#include <stdio.h>
#pragma comment (lib,"ws2_32")

int main(int argc , char* grgv[])
{
     WSADATA wsaData;
     WSAStartup(MAKEWORD(2,2),&wsaData);

     //SOCKET s = socket(PF_INET,SOCK_STREAM,IPPROTO_TCP);
     SOCKET s = socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP);

     sockaddr_in addr;
     addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
     addr.sin_port = htons(827);
     addr.sin_family = PF_INET;

     bind(s,(SOCKADDR*)&addr,sizeof(SOCKADDR));

     //listen(s,1);

     SOCKADDR clientAddr;
     int nSize = sizeof(SOCKADDR);
     //SOCKET clientSock;
     char buf[MAXBYTE] = {0};
     int len = sizeof(SOCKADDR);
     recvfrom(s,buf,MAXBYTE,0,(SOCKADDR*)&clientAddr,&len);
     printf("%s \r\n",buf);

     //clientSock = accept(s,(SOCKADDR*)&clientAddr,&nSize);
     //send(clientSock,"hello client \r\n",strlen("hello client \r\n" + sizeof(char)),NULL);

     sendto(s,"hello world client UDP",strlen("hello world client UDP") + sizeof(char),
          0,(SOCKADDR*)&clientAddr,sizeof(SOCKADDR));
    
     //closesocket(clientSock);
     closesocket(s);

     WSACleanup();
     return 0;
}