WinSock UDP通讯实例

#include <WinSock2.h> 
#include <stdio.h>
#define PORT 8888
int main() //server
{
    WSADATA wsaData;
    int Ret = WSAStartup(MAKEWORD(2,2),&wsaData);
    printf("Server!\n");
    if(Ret != 0)
    {
        printf("无法初始化winsock.\n");
        WSACleanup();
    }
    else{
        
    //    printf("初始化winsock成功\n");
    }
    
    if ( LOBYTE( wsaData.wVersion ) != 2 ||
        HIBYTE( wsaData.wVersion ) != 2 )
    {
        WSACleanup( );
        return 1; 
    }

    SOCKET socket=::socket(AF_INET,SOCK_DGRAM,IPPROTO_IP);
    sockaddr_in addr;
    addr.sin_addr.S_un.S_addr=INADDR_ANY;
    addr.sin_family=AF_INET;
    addr.sin_port=ntohs(PORT);
    
    
    
    if(socket==INVALID_SOCKET)
    {
        printf("socket Error!");
    }
    int rs=    bind(socket,(sockaddr*)&addr,sizeof(addr));
    
    if (rs!=0)
    {
        printf("bind failed!");
        return 1;
    }
    char buf[200]="\0";
    char temp[200]="\0";
    sockaddr_in addrcl;
    int len=sizeof(sockaddr);
    
    while(1){
        
        recvfrom(socket,buf,sizeof(buf),0,(sockaddr*)&addrcl,&len);//用新建的地址结构保存客户端的信息 
        
        sprintf(temp,"%s:%s",inet_ntoa(addrcl.sin_addr),buf);
        sendto(socket,temp,strlen(temp)+1,0,(sockaddr*)&addrcl,sizeof(addr));
        if(strcmp(buf,"srvexit")==0)
        {
            break;
        }
        printf("%s",buf);
    }
    closesocket(socket);
    
    WSACleanup();
    printf("exit\n");
    return 0;
}

#include <WinSock2.h>
#include <stdio.h>
#define PORT 8888
int main()
{
    WSADATA wsaData;
    int Ret = WSAStartup(MAKEWORD(2,2),&wsaData);
    printf("Client..!\n");
    if(Ret != 0)
    {
        printf("无法初始化winsock.\n");
        WSACleanup();
    }
    else{
        
    //    printf("初始化winsock成功\n");
    }
    
    SOCKET socketc=::socket(AF_INET,SOCK_DGRAM,IPPROTO_IP);
    sockaddr_in addr;
    addr.sin_addr.S_un.S_addr=inet_addr("127.0.0.1");
    addr.sin_family=AF_INET;
    addr.sin_port=ntohs(PORT);
    
    if(socketc==INVALID_SOCKET)
    {
        printf("socket Error!");
    }

    int len=sizeof(sockaddr);
    

    while (1)//client
    {
        char buf[200]="\0";
        char rbuf[300]="\0";
        printf("\n:");
        scanf("%s",&buf);
        sendto(socketc,buf,strlen(buf)+1,0,(SOCKADDR*)&addr,len);//用回原来的地址结构
    
        recvfrom(socketc,rbuf,sizeof(rbuf),0,(SOCKADDR*)&addr,&len);
        if(strcmp(rbuf,"exit")==0)
        {
            break;
        }
        printf("%s",rbuf);
        
    }
    
    closesocket(socketc);
    WSACleanup();
    printf("end\n");
    return 0;
}