Поиск всех доступных файлов в заданном каталоге

var a := EnumerateAllFiles('путь к папке', '*.*').ToArray();

System.UnauthorizedAccessException

function EnumerateAvailableFiles(path: string): sequence of string;
begin
  try
    
    Result := 
      System.IO.Directory.EnumerateFiles(path) +
      System.IO.Directory.EnumerateDirectories(path).SelectMany(EnumerateAvailableFiles);
    
  except
    on e: System.UnauthorizedAccessException do//если не даёт - тупо игнорим папку
      Result := System.Linq.Enumerable.Empty&<string>;
  end;
end;

function FindAllFiles(path, progDir:string):array of string;
begin
  var enc:Encoding := Encoding.UTF8;
  var a:Text;
  Assign(a, (progDir + 'find.txt'));
  Rewrite(a, enc);
  Writeln(a, path);
  Close(a);
  var b, x:integer;
  x := 0;
  
  repeat
      var c:array of string := System.IO.File.ReadAllLines((progDir + 'find.txt'), enc);
      b := c.Length;
      Append(a, enc);
      
      for var i:integer := x to (c.Length - 1) do
        try
          var d:array of string := System.IO.Directory.EnumerateDirectories(c[i]).ToArray();
          for var ci:integer := 0 to (d.Length - 1) do Writeln(a, d[ci]);
        except on System.Exception do
          begin
          end;
        end;
        
      Close(a);
      x := c.Length;
  until (b = System.IO.File.ReadAllLines((progDir + 'find.txt'), enc).Length);
  
  var ld:array of string := System.IO.File.ReadAllLines((progDir + 'find.txt'), enc);
  Rewrite(a, enc);
  
  for var i:integer := 0 to (ld.Length - 1) do
    try
      var pf:array of string := System.IO.Directory.EnumerateFiles(ld[i]).ToArray();
      for var ci:integer := 0 to (pf.Length - 1) do Writeln(a, pf[ci]);
    except on System.Exception do
      begin
      end;
    end;
    
    Close(a);
    Result := System.IO.File.ReadAllLines((progDir + 'find.txt'), enc);
end;