Don't use grep to filter out these entries. Unless you know what you are doing, you open yourself to security problems (missing a directory you should traverse). And if you do know what you are doing, it looks strange to someone who doesn't, and so they might want to "fix" it and hence break it.

More discussion about this issue can be found at:

• special directory entries (where blakem talks about subtle regexp issues).
• Is readdir ever deterministic? (where merlyn explains in more detail how . and .. might move around).

And in case the OP isn't aware of them, this might be the right moment to mention File::Find and File::Find::Rule.