一个简单的以太网广播收发例子

来源：互联网发布：光谷大数据产业基地编辑：程序博客网时间：2024/05/20 18:43

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#include<stdlib.h>
#include<iostream.h>
#include<conio.h>
#include<stdio.h>
#include<winsock2.h>
#include<windows.h>
#pragma comment(lib,"ws2_32.lib")
void main(void)
{
SOCKET s;
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=0;
a.sin_port=htons(5050);

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
s=socket(AF_INET,SOCK_DGRAM,0);
   //设置该套接字为广播类型，
setsockopt(s,SOL_SOCKET,SO_BROADCAST,(char FAR *)&optval,sizeof(optval));
bind(s,(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(s,buf,256,0,(struct sockaddr FAR *)&from,(int FAR *)&fromlength);
  Sleep(2000);
  printf("%s/n",buf);
  ZeroMemory(buf,256);
}
}
发
#include<stdlib.h>
#include<iostream.h>
#include<stdio.h>
#include<conio.h>
#include<winsock2.h>
#include<windows.h>

#pragma comment(lib,"ws2_32.lib")
main()
{
SOCKET s;
sockaddr_in addrto;
WSADATA wsdata;
BOOL bsocket;
char *smsg="this is a test";
//启动SOCKET库，版本为2.0
WSAStartup(0x0202,&wsdata);

s=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(5050);
bool opt=true;
//设置该套接字为广播类型，
setsockopt(s,SOL_SOCKET,SO_BROADCAST,(char FAR *)&opt,sizeof(opt));
int nlen=sizeof(addrto);
while(1)
{
  Sleep(1000);
  //从广播地址发送消息
  int ret=sendto(s,smsg,256,0,(sockaddr*)&addrto,nlen);
  if(ret==SOCKET_ERROR)
   cout<<WSAGetLastError()<<endl;
  else
  {
   printf("ok");
  }
}
}