unit NetworkUnit;

interface

uses
  Windows,
  WinSock;

type
  TNetworkInfo = record
    HostName: String;
    IPAddress: String;
  end;

function GetMachineNetworkInfo: TNetworkInfo;
function GetHostName(Ip : String) : String;
function GetIpAddress(HostName : String) : String;

implementation


{-------------------------------
//  自マシンのマシン名とIPアドレスを取得する
備考:       uses WinSockが必要
履歴:       2003/11/12
//------------------------------}
function GetMachineNetworkInfo: TNetworkInfo;
var
   wsaData  : TWsaData;
   hostName : array [0..255] of char;
   host     : PHostEnt;
   in_addr  : TInAddr;
begin
   WSAStartup($101, wsaData);
   WinSock.gethostname(hostName,sizeof(hostName));
   host     := gethostbyname(hostName);
   in_addr  :=PInAddr(PInAddr(host^.h_addr_list)^)^;
   Result.HostName :=String(hostName);
   Result.IPAddress :=String(inet_ntoa(in_addr));
   WSACleanup;
end;
//------------------------------


{-------------------------------
//  IPアドレスからhost名を求める
備考:       uses Winsockが必要
履歴:       2003/11/12
            2006/04/04 若干簡単になるように修正
//------------------------------}
function GetHostName(Ip : String) : String;
var
  PH : PHostEnt;
  InAddr: TInAddr;
  WSADATA : TWSADATA;
begin
  Result := '';
  if Ip = '' then exit;
  InAddr.S_addr := inet_addr(PChar(Ip));
  WSAStartup(MakeWord(1,1) , WSADATA);  //MakeWord(1,1)=$0101

  PH := gethostbyaddr(@InAddr,4,PF_INET);

  if PH = nil then Exit;
  Result := string(ph^.h_name);
  WSACleanup;
end;
//------------------------------

{-------------------------------
//  host名からIPアドレスを求める
備考:       uses Winsockが必要
履歴:       2006/04/04
//------------------------------}
function GetIpAddress(HostName : String) : String;
var
  PH : PHostEnt;
  InAddr: TInAddr;
  WSADATA : TWSADATA;
begin
  Result := '';
  if HostName = '' then exit;
  WSAStartup(MakeWord(1,1), WSADATA);

  PH := gethostbyname(PChar(HostName));

  if PH = nil then Exit;
  InAddr := PInAddr(ph^.h_addr_list^)^;
  Result := inet_ntoa(InAddr);
  WSACleanup;
end;
//------------------------------


end.