$ mkdir x $ cd x $ echo aa > .y $ mkdir y $ echo aa > y/z $ echo aa > y/.z $ grep -r a * y/.z:aa y/z:aa Notice that hidden files in the top-lev

$ mkdir x $ cd x $ echo aa > .y $ mkdir y $ echo aa > y/z $ echo aa > y/.z $ grep -r a * y/.z:aa y/z:aa Notice that hidden files in the top-level (.y) don't show up, but those in subdirectories (y/.z) do. It's kind of a gotcha. Fortunately one rarely finds dotfiles in subdirs.