进程间通讯（三）--套接字

套接字，是支持TCP/IP的网络通信的基本操作单元，可以看做是不同主机之间的进程进行双向通信的端点，简单的说就是通信的两方的一种约定，用套接字中的相关函数来完成通信过程。按照往例，话不多说，直接上Demo：

Server端：

// SocketServer.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <winsock2.h>
#pragma comment(lib, "WS2_32")	// 链接到WS2_32.lib
#include <WS2tcpip.h>

int main()
{

	// 初始化WS2_32.dll
	WSADATA WsaData = {0};
	WORD SocketVersion = MAKEWORD(2, 2);
	if (WSAStartup(SocketVersion, &WsaData) != 0)
	{
		printf("Can't Init Socket!\r\n");
		return 0;
	}
	// 创建套接字
	SOCKET ListenSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);//IPv4协议，TCP协议，TCP封包
	if (ListenSocket == INVALID_SOCKET)
	{
		printf("Failed socket()!\r\n");
		return 0;
	}

	// 填充sockaddr_in结构
	sockaddr_in ServerAddr;
	ServerAddr.sin_family = AF_INET;
	ServerAddr.sin_port = htons(4567);
	ServerAddr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");

	// 绑定这个套节字到一个本地地址
	if (bind(ListenSocket, (LPSOCKADDR)&ServerAddr, sizeof(ServerAddr)) == SOCKET_ERROR)
	{
		printf("Failed bind()! \r\n");
		closesocket(ListenSocket);
		WSACleanup();
		return 0;
	}

	// 进入监听模式
	if (listen(ListenSocket, 2) == SOCKET_ERROR)
	{
		printf("Failed listen()!\r\n");
		closesocket(ListenSocket);
		WSACleanup();
		return 0;
	}

	// 循环接受客户的连接请求
	sockaddr_in ClientAddr;
	int AddrLength = sizeof(ClientAddr);
	SOCKET AcceptSocket;
	char SendBuffer[] = "TCP Server! \r\n";
	while (TRUE)
	{
		// 接受一个新连接
		AcceptSocket = accept(ListenSocket, (SOCKADDR*)&ClientAddr, &AddrLength);
		if (AcceptSocket == INVALID_SOCKET)
		{
			closesocket(ListenSocket);
			WSACleanup();
			printf("Failed accept()!\r\n");
			continue;
		}
		char Buffer[16] = { 0 };
		printf("Accept a New Client：%s \r\n", inet_ntop(AF_INET, &ClientAddr.sin_addr,Buffer,16));
		// 接收数据
		char RecvBuffer[256];
		int BufferLength = recv(AcceptSocket, RecvBuffer, 256, 0);
		if (BufferLength > 0)
		{
			RecvBuffer[BufferLength] = '\0';
			printf("Recived Buffer：%s", RecvBuffer);
		}
		// 向客户端发送数据
		send(AcceptSocket, SendBuffer, strlen(SendBuffer), 0);
		// 关闭同客户端的连接
		closesocket(AcceptSocket);
	}

	// 关闭监听套节字
	closesocket(ListenSocket);
	WSACleanup();
    return 0;
}

Client端：

// SocketClient.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <winsock2.h>
#pragma comment(lib, "WS2_32")	// 链接到WS2_32.lib
#include <WS2tcpip.h>

int main()
{
	// 初始化WS2_32.dll
	WSADATA WsaData;
	WORD SocketVersion = MAKEWORD(2, 2);
	if (WSAStartup(SocketVersion, &WsaData) != 0)
	{
		printf("Can't Init Socket!\r\n");
		return 0;
	}

	// 创建套接字
	SOCKET ClientSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (ClientSocket == INVALID_SOCKET)
	{
		printf(" Failed socket()!\r\n");
		WSACleanup();
		return 0;
	}

	// 也可以在这里调用bind函数绑定一个本地地址
	// 否则系统将会自动安排

	// 填写远程地址信息
	sockaddr_in ServerAddr;
	ServerAddr.sin_family = AF_INET;
	ServerAddr.sin_port = htons(4567);
	// 注意，这里要填写服务器程序（TCPServer程序）所在机器的IP地址
	// 如果你的计算机没有联网，直接使用127.0.0.1即可
	ServerAddr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");

	if (connect(ClientSocket, (sockaddr*)&ServerAddr, sizeof(ServerAddr)) == SOCKET_ERROR)
	{
		printf(" Failed connect()!\r\n");
		closesocket(ClientSocket);
		WSACleanup();
		return 0;
	}
	char SendBuffer[] = "TCP Client Connect! \r\n";
	// 向服务端发送数据
	send(ClientSocket, SendBuffer, strlen(SendBuffer), 0);
	// 接收数据
	char RecvBuffer[256];
	int BufferLength = recv(ClientSocket, RecvBuffer, 256, 0);
	if (BufferLength > 0)
	{
		RecvBuffer[BufferLength] = '\0';
		printf(" Recived Buffer：%s", RecvBuffer);
	}

	// 关闭套节字
	closesocket(ClientSocket);
	WSACleanup();
	getchar();
	getchar();
    return 0;
}