最简单client和server通信程序

开两个vc或者建两个工程，先运行server再运行client

server端：

#include <WINSOCK2.H>
#include <stdio.h>
#pragma comment(lib,"ws2_32.lib")
void main()
{
//创建套接字
WORD myVersionRequest;
WSADATA wsaData;
myVersionRequest=MAKEWORD(1,1);
int err;
err=WSAStartup(myVersionRequest,&wsaData);
if (!err)
{
printf("已打开套接字/n");

}
else
{
//进一步绑定套接字
printf("嵌套字未打开!");
return;
}
SOCKET serSocket=socket(AF_INET,SOCK_STREAM,0);//创建了可识别套接字
//需要绑定的参数
SOCKADDR_IN addr;
addr.sin_family=AF_INET;
addr.sin_addr.S_un.S_addr=htonl(INADDR_ANY);//ip地址
addr.sin_port=htons(6000);//绑定端口

bind(serSocket,(SOCKADDR*)&addr,sizeof(SOCKADDR));//绑定完成
listen(serSocket,5);//其中第二个参数代表能够接收的最多的连接数

//////////////////////////////////////////////////////////////////////////
//开始进行监听
//////////////////////////////////////////////////////////////////////////
SOCKADDR_IN clientsocket;
int len=sizeof(SOCKADDR);
while (1)
{
SOCKET serConn=accept(serSocket,(SOCKADDR*)&clientsocket,&len);//如果这里不是accept而是conection的话。。就会不断的监听
char sendBuf[100];

sprintf(sendBuf,"welcome %s to bejing",inet_ntoa(clientsocket.sin_addr));//找对对应的IP并且将这行字打印到那里
send(serConn,sendBuf,strlen(sendBuf)+1,0);
char receiveBuf[100];//接收
recv(serConn,receiveBuf,strlen(receiveBuf)+1,0);
printf("%s/n",receiveBuf);
closesocket(serConn);//关闭
WSACleanup();//释放资源的操作
}
}

client端：

#include <WINSOCK2.H>
#include <stdio.h>
#pragma comment(lib,"ws2_32.lib")

void main()
{
int err;
WORD versionRequired;
WSADATA wsaData;
versionRequired=MAKEWORD(1,1);
err=WSAStartup(versionRequired,&wsaData);//协议库的版本信息

if (!err)
{
printf("客户端嵌套字已经打开!/n");
}
else
{
printf("客户端的嵌套字打开失败!/n");
return;//结束
}
SOCKET clientSocket=socket(AF_INET,SOCK_STREAM,0);
SOCKADDR_IN clientsock_in;
clientsock_in.sin_addr.S_un.S_addr=inet_addr("127.0.0.1");
clientsock_in.sin_family=AF_INET;
clientsock_in.sin_port=htons(6000);
//bind(clientSocket,(SOCKADDR*)&clientsock_in,strlen(SOCKADDR));//注意第三个参数
//listen(clientSocket,5);
connect(clientSocket,(SOCKADDR*)&clientsock_in,sizeof(SOCKADDR));//开始连接

char receiveBuf[100];
recv(clientSocket,receiveBuf,101,0);
printf("%s/n",receiveBuf);

send(clientSocket,"hello,this is client",strlen("hello,this is client")+1,0);
closesocket(clientSocket);
WSACleanup();
}