unit Unit2;
interface
uses
 Classes,Scktcomp,winsock;

type
 TSockThread = class(TThread)
 private
 protected
   procedure Execute; override;
 end;

implementation

function SockWaitForData(ASocket:TSocket; ATimeout: Longint): Boolean;
var
 FDSet: TFDSet;
 TimeVal: TTimeVal;
begin
 TimeVal.tv_sec := ATimeout div 1000;
 TimeVal.tv_usec := (ATimeout mod 1000) * 1000;
 FD_ZERO(FDSet);
 FD_SET(ASocket, FDSet);
 Result := select(0, @FDSet, nil, nil, @TimeVal) > 0;
end;

function SockReadLn(ASocket:TSocket;ATerminator:char;AMaxLineLength:integer;ATimeOut:Long int):string;
var
 Buf:array[byte] of char;
 SizeBuf:integer;
 r,i:integer;
 s:string;
begin
 SizeBuf:=SizeOf(Buf);
 result:='';
 while SockWaitForData(ASocket,ATimeOut) do
 begin
   r:=recv(ASocket, Buf, SizeBuf, MSG_PEEK);
   if r=SOCKET_ERROR then RaiseSocketError(WSAGetLastError, 'recv');
   i:=LCharPos(@Buf,ATerminator,r);
   if i<>0 then r:=i;
   r:=recv(ASocket, Buf, r, 0);
   if r=SOCKET_ERROR then RaiseSocketError(WSAGetLastError, 'recv');
   SetString(s,Buf,r);
   result:=result+s;
   if i<>0 then Break;
 end;
 if length(result)=0 then exit;
 i:=length(result)-1;
 if (ATerminator=LF) and (result[i]=CR) then Dec(i);
 SetLength(result,i);
end;

{ TSockThread }

procedure TSockThread.Execute;
var
 Socket:TClientWinSocket;
 s:string;
 Code:integer;
begin
 Socket:=TClientWinSocket.Create(-1);
 try
   Socket.ClientType:=ctBlocking;
   Socket.Open('192.168.14.2','','',3128);
   Socket.SendText('CONNECT hostname HTTP/1.0'#13#10);
   Socket.SendText(#13#10);
   s:=SockReadLn(Socket.SocketHandle);
   Fetch(s,' ');
   Code:=StrToIntDef(Fetch(s,' '),200);
   if Code<>200 then raise Exception.CreateFmt('Bad HTTP status code: %d %s',[Code,s]);
   repeat until
     SockReadLn(PeerSocket.SocketHandle) = '';
   ...
 finally
   Socket.Free;
 end;
end;

end.