Winsock编程基础2（UDP流程）

int sendto(
    SOCKET s,    //用来发送数据的套接字
    const char FAR *buf,    //指向发送数据的缓冲区
    int len,    //要发送数据长度
    int flags,    //一般指定0
    const struct sockaddr *to,    //指向一个包含目标地址和端口号的sockaddr_in结构
    int toLen    //结构大小
);
int recvfrom(SOCKET s, char *FAR buf, int len, int flags, struct sockaddr FAR *from, int FAR* fromLen)

#include <iostream>
#include <stdio.h>

#include "InitSock.h"

using namespace std;
int main(void)
{
    CInitSock initSock;
    //创建套接字
    SOCKET s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    if (s == INVALID_SOCKET)
    {
        cout << "Failed socke()" << endl;
        return 0;
    }

    sockaddr_in addr;
    addr.sin_family = AF_INET;
    addr.sin_port = htons(4567);
    addr.sin_addr.S_un.S_addr = INADDR_ANY;

    //绑定套接字到一个本地地址
    if (bind(s, (LPSOCKADDR)&addr, sizeof(addr)) == SOCKET_ERROR)
    {
        cout << "Failed bind()" << endl;
        return 0;
    }

    //接收数据
    char buf[1024];
    sockaddr_in clientAddr;
    int nLen = sizeof(addr);
    while (TRUE)
    {
        int nRecv = recvfrom(s, buf, 1024, 0, (sockaddr*)&clientAddr, &nLen);
        if (nRecv > 0)
        {
            buf[nRecv] = ‘\0‘;
            cout << "接收到数据" << inet_ntoa(clientAddr.sin_addr) << ": " << buf << endl;
        }
    }

    //关闭套接字
    closesocket(s);
    return 0;
}