function ScanFile(const filename: String;
                 const forString: String; // حتى ولو إستعملت WideString فهذا لايعطي اية نتيجة  
                 caseSensitive: Boolean ): LongInt;
{ returns position of string in file or -1, if not found }
const
BufferSize= $8001;  { 32K+1 bytes }
var
pBuf, pEnd, pScan, pPos : PWidechar;
filesize: LongInt;
bytesRemaining: LongInt;
bytesToRead: Integer;
F   : File;
SearchFor: PWidechar;
oldMode: Word;
begin
Result := -1;  { assume failure }
if (Length( forString ) = 0) or (Length( filename ) = 0) then
   Exit;
SearchFor := nil;
pBuf      := nil;

{ open file as binary, 1 byte recordsize }
AssignFile( F, filename );
oldMode := FileMode;
FileMode := 0;    { read-only access }
Reset( F, 1 );
FileMode := oldMode;
try { allocate memory for buffer and pchar search string }
   SearchFor := StrAllocW( Length( forString )+1 );
   StrPCopyW( SearchFor, forString );
  if not caseSensitive then  { convert to upper case }

  Tnt_WideUpperCase(SearchFor ); //
    // AnsiUpperCase( SearchFor );
   GetMem( pBuf, BufferSize );
   filesize := System.Filesize( F );
   bytesRemaining := filesize;
   pPos := nil;
   while bytesRemaining > 0 do
   begin
     { calc how many bytes to read this round }
     if bytesRemaining >= BufferSize then
       bytesToRead := Pred( BufferSize )
     else
       bytesToRead := bytesRemaining;

     { read a buffer full and zero-terminate the buffer }
     BlockRead(F, pBuf^, bytesToRead, bytesToRead);
     pEnd := @pBuf[ bytesToRead ];
     pEnd^:= #0;
     { scan the buffer. Problem: buffer may contain #0 chars! So we
       treat it as a concatenation of zero-terminated strings. }
     pScan := pBuf;
     while pScan < pEnd do
     begin
      if not caseSensitive then { convert to upper case }
        Tnt_WideUpperCase( pScan );
       pPos := StrPosW( pScan, SearchFor );  { search for substring }
       if pPos <> nil then
       begin { Found it! }
         Result := FileSize - bytesRemaining +
                   LongInt( pPos ) - LongInt( pBuf );
         Break;
       end;
       pScan := StrEndW( pScan );
       Inc( pScan );
     end;
     if pPos <> nil then
       Break;
     bytesRemaining := bytesRemaining - bytesToRead;
     if bytesRemaining > 0 then
     begin
     { no luck in this buffers load. We need to handle the case of
       the search string spanning two chunks of file now. We simply
       go back a bit in the file and read from there, thus inspecting
       some characters twice
     }
       Seek( F, FilePos(F)-Length( forString ));
       bytesRemaining := bytesRemaining + Length( forString );
     end;
   end; { While }
finally
   CloseFile( F );
   If SearchFor <> nil then
     StrDisposeW( SearchFor );
   If pBuf <> nil then
     FreeMem( pBuf, BufferSize );
end;
end; { ScanFile }
procedure GetFileList( FileList: TStringList; inDir, Extension : String );
procedure ProcessSearchRec( aSearchRec : TSearchRecW );
var
  sDate: String;
begin
   if ( aSearchRec.Attr and faDirectory ) <> 0 then
   begin
     if ( aSearchRec.Name <> '.' ) and
        ( aSearchRec.Name <> '..' ) then
     begin
       GetFileList( FileList, Extension, InDir + '\' + aSearchRec.Name );
     end;
   end
   else
   begin
     sDate := DateTimeToStr(FileDateToDateTime(aSearchRec.Time));
     FileList.Add(inDir + '\' + aSearchRec.Name);

   end;

end;

var CurDir : String;
aSearchRec : TSearchRecW;
begin
CurDir := inDir + '\*.' + Extension;
if WideFindFirst( CurDir, faAnyFile, aSearchRec ) = 0 then
begin
   ProcessSearchRec( aSearchRec );
   while WideFindNext( aSearchRec ) = 0 do
     ProcessSearchRec( aSearchRec );
end;
WideFindClose(aSearchRec);

end;



procedure TForm1.GetHTMLFileList(Directory, SearchString: WideString;
  CaseSens: Boolean);
var
FL: TStringList;
begin
FL := TStringList.Create;
FL.Sorted := True;
GetFileList(FL, Directory, 'HTM*');
ProcessHTMLFIles(FL, SearchString, CaseSens);
FL.Free;
end;


procedure TForm1.ProcessHTMLFiles(FileList: TStringList;
  SearchString: WideString; CaseSens: Boolean);
var
i: Integer;
begin
for i := 0 to Pred(FileList.Count) do
begin
   if ScanFile(FileList.Strings[i], SearchString, CaseSens) > 0 then
   begin
     // The result was found
     Memo1.Lines.Add(FileList.Strings[i]); // هنا استعمل  TntMemo لإظهار إسم الملفات التي تحتوي على الكلمة المراد البحث عنها
   end;
end;
end;