delphi Sockets检查端口是否开放

program CheckTCP_PortOpen;

{$APPTYPE CONSOLE}

uses

  Winsock;

//Windows Sockets API Unit

    function PortTCPIsOpen(dwPort : Word; ipAddressStr:string) : boolean;

    var

      client : sockaddr_in;//sockaddr_in is used by Windows Sockets to specify a local or remote endpoint address

      sock   : Integer;

    begin

        client.sin_family      := AF_INET;

        client.sin_port        := htons(dwPort);//htons converts a u_short from host to TCP/IP network byte order.

        client.sin_addr.s_addr := inet_addr(pansichar(ipAddressStr)); //the inet_addr function converts a string containing an IPv4 dotted-decimal address into a proper address for the IN_ADDR structure.

        sock  :=socket(AF_INET, SOCK_STREAM, 0);//The socket function creates a socket

        Result:=connect(sock,client,SizeOf(client))=0;//establishes a connection to a specified socket.

    end;

var

  ret    : Integer;

  wsdata : WSAData;

begin

  Writeln('Init WinSock');

  ret := WSAStartup($0002, wsdata);//initiates use of the Winsock

  if ret<>0 then exit;

  try

    Writeln('Description : '+wsData.szDescription);

    Writeln('Status      : '+wsData.szSystemStatus);

   if PortTCPIsOpen(80,'127.0.0.1 ') then

    Writeln('Open')

    else

    Writeln('Close');

  finally

  WSACleanup; //terminates use of the Winsock

  end;

  Readln;

end.