socket（套接字）

客户端：

创建套接字（socket）

连接服务器（connect）

通信（send，recv或者write，read）

关闭套接字（closesocket）

示例代码：

int main(int argc, char* argv[])
{
const int BUF_SIZE = 64;
WSADATA            wsd;            //WSADATA变量
SOCKET            sHost;            //服务器套接字
SOCKADDR_IN        servAddr;        //服务器地址
char            buf[BUF_SIZE];    //接收数据缓冲区
char            bufRecv[BUF_SIZE];
int                retVal;            //返回值

//初始化套结字动态库
if (WSAStartup(MAKEWORD(2, 2), &wsd) != 0)
{
cout << "WSAStartup failed!" << endl;
return -1;
}

//创建套接字
sHost = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (INVALID_SOCKET == sHost)
{
cout << "socket failed!" << endl;
WSACleanup();//释放套接字资源
return  -1;
}
//设置服务器地址
servAddr.sin_family = AF_INET;
servAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
servAddr.sin_port = htons((short)4999);
int    nServAddlen = sizeof(servAddr);
//连接服务器
retVal = connect(sHost, (LPSOCKADDR)&servAddr, sizeof(servAddr));
if (SOCKET_ERROR == retVal)
{
cout << "connect failed!" << endl;
closesocket(sHost);    //关闭套接字
WSACleanup();        //释放套接字资源
return -1;
}
while (true){
//向服务器发送数据
ZeroMemory(buf, BUF_SIZE);
cout << " 向服务器发送数据:  ";
cin >> buf;
retVal = send(sHost, buf, strlen(buf), 0);
if (SOCKET_ERROR == retVal)
{
cout << "send failed!" << endl;
closesocket(sHost);    //关闭套接字
WSACleanup();        //释放套接字资源
return -1;
}
//RecvLine(sHost, bufRecv);
recv(sHost, bufRecv, 5, 0);        // 接收服务器端的数据， 只接收5个字符
cout << endl << "从服务器接收数据：" << bufRecv;
}
//退出
closesocket(sHost);    //关闭套接字
WSACleanup();        //释放套接字资源
return 0;
}

服务端：

创建套接字（socket）

绑定套接字（bind）

开启监听（listen）

接受请求（accept）

通信（send，recv或者write，read）

关闭套接字（closesocket）

示例代码：

int _tmain(int argc, char* argv[])
{
const int BUF_SIZE = 64;
WSADATA            wsd;            //WSADATA变量
SOCKET            sServer;        //服务器套接字
SOCKET            sClient;        //客户端套接字
SOCKADDR_IN        addrServ;;        //服务器地址
char            buf[BUF_SIZE];    //接收数据缓冲区
char            sendBuf[BUF_SIZE];//返回给客户端得数据
int                retVal;            //返回值
//初始化套结字动态库
if (WSAStartup(MAKEWORD(2, 2), &wsd) != 0)
{
cout << "WSAStartup failed!" << endl;
return 1;
}

//创建套接字
sServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (INVALID_SOCKET == sServer)
{
cout << "socket failed!" << endl;
WSACleanup();//释放套接字资源;
return  -1;
}

//服务器套接字地址
addrServ.sin_family = AF_INET;
addrServ.sin_port = htons(4999);
addrServ.sin_addr.s_addr = INADDR_ANY;
//绑定套接字
retVal = bind(sServer, (LPSOCKADDR)&addrServ, sizeof(SOCKADDR_IN));
if (SOCKET_ERROR == retVal)
{
cout << "bind failed!" << endl;
closesocket(sServer);    //关闭套接字
WSACleanup();            //释放套接字资源;
return -1;
}

//开始监听
retVal = listen(sServer, 1);
if (SOCKET_ERROR == retVal)
{
cout << "listen failed!" << endl;
closesocket(sServer);    //关闭套接字
WSACleanup();            //释放套接字资源;
return -1;
}

//接受客户端请求
sockaddr_in addrClient;
int addrClientlen = sizeof(addrClient);
sClient = accept(sServer, (sockaddr FAR*)&addrClient, &addrClientlen);
if (INVALID_SOCKET == sClient)
{
cout << "accept failed!" << endl;
closesocket(sServer);    //关闭套接字
WSACleanup();            //释放套接字资源;
return -1;
}

while (true){
//接收客户端数据
ZeroMemory(buf, BUF_SIZE);
retVal = recv(sClient, buf, BUF_SIZE, 0);
if (SOCKET_ERROR == retVal)
{
cout << "recv failed!" << endl;
closesocket(sServer);    //关闭套接字
closesocket(sClient);    //关闭套接字
WSACleanup();            //释放套接字资源;
return -1;
}
if (buf[0] == '0')
break;
cout << "客户端发送的数据: " << buf << endl;

cout << "向客户端发送数据: ";
cin >> sendBuf;

send(sClient, sendBuf, strlen(sendBuf), 0);
}

//退出
closesocket(sServer);    //关闭套接字
closesocket(sClient);    //关闭套接字
WSACleanup();            //释放套接字资源;

return 0;
}