基于UDP的控制台聊天程序

（1）服务器端程序

#include<winsock2.h>
#include<stdio.h>
//////////////////////////////////////////////////////////////////////////////////////////////////
//控制台聊天程序服务器端程序//
/////////////////////////////////////////////////////////////////////////////////////////////////
void main()
{
/*用WSASTARTUP来启动有关socket的动态链接库*/
WORD wVersionRequested;
WSADATA wsaData;
int err;
wVersionRequested = MAKEWORD( 2, 2 );
err = WSAStartup( wVersionRequested, &wsaData );
if ( err != 0 ) {
return;
}
if ( LOBYTE( wsaData.wVersion ) != 2 ||
        HIBYTE( wsaData.wVersion ) != 2 ) {
  WSACleanup( );
  return;
}
SOCKET sockSrv=socket(AF_INET,SOCK_DGRAM,0);
SOCKADDR_IN addrSrv;
addrSrv.sin_addr.S_un.S_addr=htonl(INADDR_ANY);
addrSrv.sin_family=AF_INET;
addrSrv.sin_port=htons(6000);
bind(sockSrv,(SOCKADDR*)&addrSrv,sizeof(SOCKADDR));//套接字与端口信息绑定
SOCKADDR_IN addrClient;
int len=sizeof(SOCKADDR);
char recvBuf[100];
memset(recvBuf,0,100);
char sendBuf[100];
memset(sendBuf,0,100);
char tempBuf[100];
memset(tempBuf,0,100);
while(1)
{
  recvfrom(sockSrv,recvBuf,100,0,(SOCKADDR*)&addrClient,&len);//无需监听及接收连接，直接接收客户端发来的信息
  if('q'==recvBuf[0])//如否客户端发来‘q’,则停止聊天
  {
   sendto(sockSrv,"q",sizeof("q")+1,0,(SOCKADDR*)&addrClient,len);
   printf("Chat End!");
   break;
  }
  //如果客户端没有要求停止聊天，则打印客户端的信息，并向客户端发送信息
  sprintf(tempBuf,"%s says :%s",inet_ntoa(addrClient.sin_addr),recvBuf);
  printf("%s\n",tempBuf);
  printf("please input data:\n");
  gets(sendBuf);
  sendto(sockSrv,sendBuf,strlen(sendBuf)+1,0,(SOCKADDR*)&addrClient,len);
}
closesocket(sockSrv);//关闭套接字
WSACleanup();//关闭WSA
}

（2）客户端程序

#include<winsock2.h>
#include<stdio.h>
/////////////////////////////////////////////////////////////////////////////////////
//面向UDP控制台聊天程序,客户端//
////////////////////////////////////////////////////////////////////////////////////
void main()
{
/*用WSASTARTUP来启动有关socket的动态链接库*/
WORD wVersionRequested;
WSADATA wsaData;
int err;
wVersionRequested = MAKEWORD( 2, 2 );
err = WSAStartup( wVersionRequested, &wsaData );
if ( err != 0 ) {
return;
}
if ( LOBYTE( wsaData.wVersion ) != 2 ||
        HIBYTE( wsaData.wVersion ) != 2 ) {
  WSACleanup( );
  return;
}
SOCKET sockClient=socket(AF_INET,SOCK_DGRAM,0);
SOCKADDR_IN addrSrv;
addrSrv.sin_addr.S_un.S_addr=inet_addr("127.0.0.1");
addrSrv.sin_family=AF_INET;
addrSrv.sin_port=htons(6000);
char recvBuf[100];
memset(recvBuf,0,100);
char sendBuf[100];
memset(sendBuf,0,100);
char tempBuf[100];
memset(tempBuf,0,100);
int len=sizeof(SOCKADDR);
while(1)
{
  printf("please input data:");
  gets(sendBuf);
  sendto(sockClient,sendBuf,strlen(sendBuf)+1,0,(SOCKADDR*)&addrSrv,len);
  recvfrom(sockClient,recvBuf,100,0,(SOCKADDR*)&addrSrv,&len);
  if('q'==recvBuf[0])
  {
   sendto(sockClient,"q",strlen("q")+1,0,(SOCKADDR*)&addrSrv,len);
   printf("Chat end!");
   break;
  }
  sprintf(tempBuf,"%s says :%s",inet_ntoa(addrSrv.sin_addr),recvBuf);
  printf("%s\n",tempBuf);
}
closesocket(sockClient);
WSACleanup();

}