扫描给定范围端口是否开放

#include <tchar.h>#include <string.h>#include <WinSock.h>#include <iostream>#pragma comment(lib,"ws2_32.lib")using namespace std;int _tmain(int argc, _TCHAR* argv[]){   int m,n;    //初始化Windows Sockets 动态库    WSADATA wsaData;    if(WSAStartup(MAKEWORD(2,2),&wsaData)!=0)    {        cout<<"找不到可使用的WinSock dll!"<<endl;        return 1;    }    SOCKET sClient = NULL;    SOCKADDR_IN addrServ;    addrServ.sin_family=AF_INET;    addrServ.sin_addr.S_un.S_addr=inet_addr("127.0.0.1");    printf("请输入要扫描的端口范围（例如1-1024）：");    scanf("%d-%d",&m,&n);    if(m > n)        printf("输入错误请重新输入！");    for (int _port = m;_port<=n;_port++){        if (sClient == NULL)        {            //创建套接字            sClient=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);            if(sClient==INVALID_SOCKET)            {                cout<<"创建客户端socket失败！"<<endl;                return 1;            }        }    addrServ.sin_port=htons(_port);    //连接服务器    if(connect(sClient,(sockaddr *)&addrServ,sizeof(sockaddr))==SOCKET_ERROR)    {        cout<<"port "<<_port<<" is not open！"<<endl;   //closesocket(sClient);        //return 1;    }    else{        cout<<"port "<<_port<<" open on host!!!!!!!!!!!!"<<endl;        closesocket(sClient);        sClient = NULL;    }}    //关闭套接字，释放资源    getchar();    WSACleanup();    return 0;}