基于C++简单Windows API的socket编程（阻塞模式）

1. 概述：简单的基于Windows API的socket点对点聊天程序，为了方便初学者，本文代码均采用阻塞原理编写。

2. 代码样例

Server.cpp（服务端）

#include <cstdio>
#include <cstdlib>
#include <iostream>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <Winsock2.h>

using namespace std;

#pragma comment(lib,"ws2_32.lib")

const short HOST_PORT = 4500;
const char *HOST_IP = "127.0.0.1";

int main(void)
{
	int maxConnectTimeout = 20;
	char revData[255] = "\0";
	sockaddr_in sain;
	sockaddr_in remote_sain;
	SOCKET sClient;
	SOCKET sServer;
	WSADATA wsaData;
	int remoteLen = sizeof(remote_sain);
	WORD sockVersion = MAKEWORD(2,2);
	if (WSAStartup(sockVersion,&wsaData) != 0)
	{
		return 0;
	}
	sServer = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
	if (sServer == INVALID_SOCKET)
	{
		printf("[-] SOCKET CREATE ERROR\n");
		return 0;
	}else{
		printf("[*] SOCKET CREATE SUCCESS\n");
	}
	sain.sin_family = AF_INET;
	sain.sin_port = htons(HOST_PORT);
	sain.sin_addr.S_un.S_addr = INADDR_ANY;

	if (bind(sServer,(SOCKADDR*)&sain,sizeof(sain)) == SOCKET_ERROR)
	{
		printf("[-]CANNOT BIND\n");
		return 0;
	}else{
		printf("[*]BIND SUCCESS\n");
	}

	if (listen(sServer,5) == SOCKET_ERROR)
	{
		printf("[-]LISTENING ERROR\n");
		return 0;
	}else{
		printf("[*]LISTENING SUCCESS\n");
	}
	while(1)
	{
		printf("\n[*]Listening Remote-PC ...\n\n");
		sClient = accept(sServer,(SOCKADDR*)&remote_sain,&remoteLen);
 		if (sClient == INVALID_SOCKET)
 		{
			printf("[-]SOCKET RECV ERROR ...");
 			continue;
 		}
		printf("[+]PC from %s \n",inet_ntoa(remote_sain.sin_addr));
		while (1)
		{
			int ret = recv(sClient,revData,255,0);
			if (ret > 0)
			{
				revData[ret] ='\0';
				printf("%s\n",revData);
			}
		}
		closesocket(sClient);
		break;
	}
	printf("[-]Server OFF!");
	closesocket(sServer);
	WSACleanup();
	return 0;
}

Client.cpp（客户端）

#include <cstdio>
#include <cstdlib>
#include <iostream>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <Winsock2.h>

using namespace std;

#pragma comment(lib,"ws2_32.lib")

const short HOST_PORT = 4500;
const char *HOST_IP = "127.0.0.1";

int main(void)
{
	int Recvret = 0;
	char Sendbuff[255] = "\0";
	char Recvbuff[255] = "\0";
	WSADATA wsData;
	WORD sockVersion = MAKEWORD(2,2);
	sockaddr_in Remote_sain;
	if (WSAStartup(sockVersion,&wsData) != 0)
	{
		printf("[-]SOCKET STARTUP ERROR\n");
		return 0;
	}else{
		printf("[*]SOCKET STARTUP SUCCESS\n");
	}

	SOCKET sClient = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
	if (sClient == INVALID_SOCKET)
	{
		printf("[-]SOCKET CREATE ERROR\n");
		return 0;
	}else{
		printf("[*]SOCKET CREATE SUCCESS\n");
	}

	Remote_sain.sin_addr.S_un.S_addr = inet_addr(HOST_IP);
	Remote_sain.sin_port = htons(HOST_PORT);
	Remote_sain.sin_family = AF_INET;
	if (connect(sClient,(SOCKADDR*)&Remote_sain,sizeof(Remote_sain)) == SOCKET_ERROR)
	{
		printf("[-]Can not connect to the Server\n");
		closesocket(sClient);
		return 0;
	}else{
		printf("[*]Listening to %s:%d ...OK\n",HOST_IP,HOST_PORT);
	}

	while (1)
	{
		if (Recvret = recv(sClient,Recvbuff,255,0) != 0)
		{
			Recvbuff[Recvret] = '\0';
			printf("[*]Server(%s):\n",HOST_IP);
		}
		gets(Sendbuff);
		send(sClient,Sendbuff,255,0);
		printf("[*]Client:%s\n",Sendbuff);
	}
	closesocket(sClient);
	return 0;
}