* SocketDemo.cpp

/*****************************************************************************************************************************
*1、加载套接字库，创建套接字（WSAStartup() / socket()）;
*2、绑定套接字到一个IP地址和一个端口上（bind()）;
*3、将套接字设置为监听模式等待连接请求；
* 4、请求到来之后，接受连接请求，返回一个新的对应于此次连接的套接字(accept());
*5、用返回的套接字和客户端进行通信（send() / recv()）;
*6、返回，等待另一个连接请求
* 7、关闭套接字，关闭加载的套接字库(closesocket() / WSACleanup());
*****************************************************************************************************************************/
#include 
#include 
#include 
using namespace std;
#pragma comment(lib,"ws2_32.lib")void reverse(char* p, char* q) {if (p > q) { swap(p, q); }char t = NULL;for (; p < q; p++, q--) {t = *p;*p = *q;*q = t;}
}void ntoa(char *addr, ULONG ip) {UINT8 a, b, c, d;char* p = addr, * q = NULL;d = ip >> 24;c = (ip & 0x00ffffff) >> 16;b = (ip & 0x0000ffff) >> 8;a = (ip & 0x000000ff);q = p;do {*p = a % 10 + 48;a /= 10;p++;} while (a > 0);reverse(q, p - 1);*p++ = '.';q = p;do {*p = b % 10 + 48;b /= 10;p++;} while (b > 0);reverse(q, p - 1);*p++ = '.';q = p;do {*p = c % 10 + 48;c /= 10;p++;} while (c > 0);reverse(q, p - 1);*p++ = '.';q = p;do {*p = d % 10 + 48;d /= 10;p++;} while (d > 0);reverse(q, p - 1);*p = '\0';
}int main()
{//初始化WSAWORD sockVersion = MAKEWORD(2, 2);WSADATA wsaData;//WSADATA结构体变量的地址值const int port = 8090;//int WSAStartup(WORD wVersionRequested, LPWSADATA lpWSAData);//成功时会返回0，失败时返回非零的错误代码值if (WSAStartup(sockVersion, &wsaData) != 0){cout << "WSAStartup() error!" << endl;return 0;}//创建套接字SOCKET slisten = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);if (slisten == INVALID_SOCKET){cout << "socket error !" << endl;return 0;}//绑定IP和端口sockaddr_in sin;//ipv4的指定方法是使用struct sockaddr_in类型的变量sin.sin_family = AF_INET;sin.sin_port = htons(port);//设置端口。htons将主机的unsigned short int转换为网络字节顺序sin.sin_addr.S_un.S_addr = INADDR_ANY;//IP地址设置成INADDR_ANY，让系统自动获取本机的IP地址//bind函数把一个地址族中的特定地址赋给scket。if (bind(slisten, (LPSOCKADDR)&sin, sizeof(sin)) == SOCKET_ERROR){cout << "bind error !" << WSAGetLastError() << endl;}//开始监听if (listen(slisten, SOMAXCONN) == SOCKET_ERROR){cout << "listen error !" << endl;return -1;}//循环接收数据SOCKET sclient;sockaddr_in remoteAddr;//sockaddr_in常用于socket定义和赋值,sockaddr用于函数参数int nAddrlen = sizeof(remoteAddr);char revData[255];char addr[16];while (true){cout << "等待连接... 0.0.0.0:" << port << endl;sclient = accept(slisten, (sockaddr*)&remoteAddr, &nAddrlen);if (sclient == INVALID_SOCKET){cout << "accept error !" << endl;continue;}// inet_ntop(AF_INET, (sockaddr*)&remoteAddr, ipAddr, 16);ntoa(addr, remoteAddr.sin_addr.s_addr);cout << "接收到一个连接：" << addr << endl;// 接收数据int ret = recv(sclient, revData, 255, 0);if (ret > 0 && ret < 255){revData[ret] = 0x00;cout << revData << endl;}// 发送数据const char* sendData = "你好，TCP客户端！\n";send(sclient, sendData, (int)strlen(sendData), 0);closesocket(sclient);}closesocket(slisten);WSACleanup();system("pause");//return 0;
}// Tips for Getting Started: 
//   1. Use the Solution Explorer window to add/manage files
//   2. Use the Team Explorer window to connect to source control
//   3. Use the Output window to see build output and other messages
//   4. Use the Error List window to view errors
//   5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project
//   6. In the future, to open this project again, go to File > Open > Project and select the .sln file

telnet连接测试:

手机、电脑连同一个wifi，代理设置成电脑的ip

无线局域网适配器 WLAN:

   连接特定的 DNS 后缀 . . . . . . . :
   IPv6 地址 . . . . . . . . . . . . : 240e:878:d5:b560:550b:562c:730d:9764
   临时 IPv6 地址. . . . . . . . . . : 240e:878:d5:b560:14d2:fbfb:711e:3b39
   本地链接 IPv6 地址. . . . . . . . : fe80::a184:41cd:9359:4468%22
   IPv4 地址 . . . . . . . . . . . . : 192.168.1.100
   子网掩码  . . . . . . . . . . . . : 255.255.255.0
   默认网关. . . . . . . . . . . . . : fe80::1234%22
                                       192.168.1.1

 服务端接收到的数据:

等待连接... 0.0.0.0:8090
接收到一个连接：192.168.1.102
CONNECT dict.youdao.com:443 HTTP/1.1
Host: dict.youdao.com
Proxy-Connection: keep-alive
Connection: keep-alive