The Client for an Internet Access Control Application

The next function is responsible for disabling mouse and keyboard access:

//screenblock function

function TForm1.FuncAvail(dllName, funcName: string; var p: pointer): boolean;

var

lib: THandle;

begin

result := false;

p := nil;

if LoadLibrary(PChar(dllName)) = 0 then exit;

lib := GetModuleHandle(PChar(dllName)) ;

if lib <> 0 then

begin

p := GetProcAddress(lib, PChar(funcName)) ;

if p <> nil then Result := true;

end;

end;

//***********end screenblock function

The parse functions should be familiar to you by now. They are responsible for breaking up text that is sent by the server to the client, as demonstrated above. The code for the function is listed below:

//*******string functions

function ParseString(s : string; var Token1,Token2,Token3: string) :

boolean;

var

P1,P2 : integer;

begin

P1 := Pos(':',s);

P2 := Pos('@',s);

//Test if both delimiters are present, in the right order and

//at least 1 char apart

if ((P1 > 0) and (P2 > 0) and (P2 > P1) and (Abs(P2-P1) > 1))

then begin

Token1 := Copy(s,1,P1-1);

Token2 := Copy(s,P1+1,P2-P1-1);

Token3 := Copy(s,P2+1,Length(s)-P2);

Result := True; //valid string

end

else Result := False; //invalid string

end;

//*****end string