delphi中有这两个函数吗

function isFile(fileName:string):boolean;
var
  search:TSearchRec;
  ret:integer;
begin
  ret:=FindFirst(filename,faanyfile,search);
  if ret=0 do
  if ((search.Att and fadirectory)=faDirectory)
  then showmessage('这是一个目录')
  else begin
         result:=true;
         showmessage('这是一个文件');
       end;
end;