两段网上抄的例子, 再加上一些特别的回复. 主要用于自动查找服务器, 方便DEBUG的.
流程是由客户端进行广播, 服务器收到广播后回复自己的IP给客户端, 实现客户端自动查找服务器使用的. 之前发的测试程序被抱怨要慢慢输入服务器IP, 现在搞个自动查找的, 不过没搞完....客户端// UDPBroadcastSend.cpp : Defines the entry point for the console application.
//#include "stdafx.h"
#include<stdio.h>
#include <iostream>
#include<winsock2.h>
#include<windows.h>
#pragma comment(lib,"ws2_32.lib") using namespace std;int _tmain(int argc, _TCHAR* argv[])
{
SOCKET sock;
sockaddr_in addrto;
WSADATA wsdata;
bool bsocket;
char smsg[100] = {0};
cout<<"input what message to send\n:"<<endl;
cin>>smsg;
//启动SOCKET库,版本为2.0
WSAStartup(0x0202,&wsdata); sock=WSASocket(AF_INET,SOCK_DGRAM,0,NULL,0,WSA_FLAG_OVERLAPPED);
bsocket=true;
//然后赋值给地址,用来从网络上的广播地址接收消息;
addrto.sin_family=AF_INET;
addrto.sin_addr.s_addr=INADDR_BROADCAST;
addrto.sin_port=htons(9000);
bool opt=true;
//设置该套接字为广播类型,
setsockopt(sock,SOL_SOCKET,SO_BROADCAST,(char FAR *)&opt,sizeof(opt));
int nlen=sizeof(addrto);
char buf[100] = {0};
while(1)
{
addrto.sin_family=AF_INET;
addrto.sin_addr.s_addr=INADDR_BROADCAST;
addrto.sin_port=htons(9000); Sleep(1000);
//从广播地址发送消息
int ret=sendto(sock,smsg, strlen(smsg) + 1,0,(sockaddr*)&addrto,nlen);
if(ret==SOCKET_ERROR)
{
printf("%d/n",WSAGetLastError());
}
else
{
printf("It'sock OK.\n");
} ret = recvfrom( sock, buf, sizeof(buf), 0, (sockaddr*)&addrto, &nlen );
if (SOCKET_ERROR == ret)
{
printf("error on recv after send!\n");
}
else
{
printf("recv after send: %s\n", buf);
}
}
return 0;
}
服务器端:// UDPBroadcastRecv.cpp : Defines the entry point for the console application.
//#include "stdafx.h"
#include<stdio.h>
#include<winsock2.h>
#include<windows.h>
#pragma comment(lib,"ws2_32.lib") int _tmain(int argc, _TCHAR* argv[])
{
SOCKET sock;
sockaddr_in from,a;
WSADATA wsdata;
bool optval;
//启动SOCKET库,版本为2.0
WSAStartup(0x0202,&wsdata);
optval=true;
//然后赋值给两个地址,一个用来绑定套接字,一个用来从网络上的广播地址接收消息;
a.sin_family=AF_INET;
a.sin_addr.s_addr=INADDR_ANY;
a.sin_port=htons(9000);
from.sin_family=AF_INET;
from.sin_addr.s_addr=INADDR_BROADCAST;
from.sin_port=htons(5050); int fromlength=sizeof(SOCKADDR);
//用UDP初始化套接字
sock=socket(AF_INET,SOCK_DGRAM,0);
// 设置该套接字为广播类型,
setsockopt(sock,SOL_SOCKET,SO_BROADCAST,(char FAR *)&optval,sizeof(optval));
// 把该套接字绑定在一个具体的地址上
bind(sock,(sockaddr *)&a,sizeof(sockaddr_in));
char buf[256];
while(1)
{//从广播地址接收消息,注意用来绑定的地址和接收消息的地址是不一样的
recvfrom(sock,buf,256,0,(struct sockaddr FAR *)&from,(int FAR *)&fromlength);
//Sleep(2000);
printf("%sock\n",buf);
sendto( sock, buf, strlen(buf) + 1, 0, (struct sockaddr FAR *)&from, fromlength );
ZeroMemory(buf,256);
}
return 0;
}
流程是由客户端进行广播, 服务器收到广播后回复自己的IP给客户端, 实现客户端自动查找服务器使用的. 之前发的测试程序被抱怨要慢慢输入服务器IP, 现在搞个自动查找的, 不过没搞完....客户端// UDPBroadcastSend.cpp : Defines the entry point for the console application.
//#include "stdafx.h"
#include<stdio.h>
#include <iostream>
#include<winsock2.h>
#include<windows.h>
#pragma comment(lib,"ws2_32.lib") using namespace std;int _tmain(int argc, _TCHAR* argv[])
{
SOCKET sock;
sockaddr_in addrto;
WSADATA wsdata;
bool bsocket;
char smsg[100] = {0};
cout<<"input what message to send\n:"<<endl;
cin>>smsg;
//启动SOCKET库,版本为2.0
WSAStartup(0x0202,&wsdata); sock=WSASocket(AF_INET,SOCK_DGRAM,0,NULL,0,WSA_FLAG_OVERLAPPED);
bsocket=true;
//然后赋值给地址,用来从网络上的广播地址接收消息;
addrto.sin_family=AF_INET;
addrto.sin_addr.s_addr=INADDR_BROADCAST;
addrto.sin_port=htons(9000);
bool opt=true;
//设置该套接字为广播类型,
setsockopt(sock,SOL_SOCKET,SO_BROADCAST,(char FAR *)&opt,sizeof(opt));
int nlen=sizeof(addrto);
char buf[100] = {0};
while(1)
{
addrto.sin_family=AF_INET;
addrto.sin_addr.s_addr=INADDR_BROADCAST;
addrto.sin_port=htons(9000); Sleep(1000);
//从广播地址发送消息
int ret=sendto(sock,smsg, strlen(smsg) + 1,0,(sockaddr*)&addrto,nlen);
if(ret==SOCKET_ERROR)
{
printf("%d/n",WSAGetLastError());
}
else
{
printf("It'sock OK.\n");
} ret = recvfrom( sock, buf, sizeof(buf), 0, (sockaddr*)&addrto, &nlen );
if (SOCKET_ERROR == ret)
{
printf("error on recv after send!\n");
}
else
{
printf("recv after send: %s\n", buf);
}
}
return 0;
}
服务器端:// UDPBroadcastRecv.cpp : Defines the entry point for the console application.
//#include "stdafx.h"
#include<stdio.h>
#include<winsock2.h>
#include<windows.h>
#pragma comment(lib,"ws2_32.lib") int _tmain(int argc, _TCHAR* argv[])
{
SOCKET sock;
sockaddr_in from,a;
WSADATA wsdata;
bool optval;
//启动SOCKET库,版本为2.0
WSAStartup(0x0202,&wsdata);
optval=true;
//然后赋值给两个地址,一个用来绑定套接字,一个用来从网络上的广播地址接收消息;
a.sin_family=AF_INET;
a.sin_addr.s_addr=INADDR_ANY;
a.sin_port=htons(9000);
from.sin_family=AF_INET;
from.sin_addr.s_addr=INADDR_BROADCAST;
from.sin_port=htons(5050); int fromlength=sizeof(SOCKADDR);
//用UDP初始化套接字
sock=socket(AF_INET,SOCK_DGRAM,0);
// 设置该套接字为广播类型,
setsockopt(sock,SOL_SOCKET,SO_BROADCAST,(char FAR *)&optval,sizeof(optval));
// 把该套接字绑定在一个具体的地址上
bind(sock,(sockaddr *)&a,sizeof(sockaddr_in));
char buf[256];
while(1)
{//从广播地址接收消息,注意用来绑定的地址和接收消息的地址是不一样的
recvfrom(sock,buf,256,0,(struct sockaddr FAR *)&from,(int FAR *)&fromlength);
//Sleep(2000);
printf("%sock\n",buf);
sendto( sock, buf, strlen(buf) + 1, 0, (struct sockaddr FAR *)&from, fromlength );
ZeroMemory(buf,256);
}
return 0;
}
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