sotest_udp.cpp

windows S/C socket example.

#include <stdio.h>
#include <Winsock2.h>

void main()
{
SOCKET socket1;

//InitWinsock();
 WSADATA wsaData;
    int iErrorCode;
    if (WSAStartup(MAKEWORD(2,1),&wsaData)) //调用Windows Sockets DLL
    {
         printf("Winsock无法初始化!\n");
         WSACleanup();
         return;
    }

    printf("服务器开始创建SOCKET。\n");
struct sockaddr_in local;
struct sockaddr_in from;
int fromlen =sizeof(from);
local.sin_family=AF_INET;
local.sin_port=htons(2701); ///监听端口
local.sin_addr.s_addr=INADDR_ANY; ///本机

socket1=socket(AF_INET,SOCK_DGRAM,0);
bind(socket1,(struct sockaddr*)&local,sizeof(local));
while (1)
{
char buffer[1024]="\0";
printf("waiting for message from others-------------\n");
if (recvfrom(socket1,buffer,sizeof(buffer),0,(struct sockaddr*)&from,&fromlen)!=SOCKET_ERROR)
{
printf("Received datagram from %s--%s\n",inet_ntoa(from.sin_addr),buffer);
////给cilent发信息
sendto(socket1,buffer,sizeof(buffer),0,(struct sockaddr*)&from,fromlen);

}
//Sleep(1000);
}
closesocket(socket1);
}