Why do directory listings contain the current (.) and parent (..) directory?

Question

Whenever I list the contents of a directory with a function like readdir, the returned file names also include \".\" and \"..\". I have the suspicion that these are just nor

Answer 1

Because on Unix-like operating systems, the directory-listing commands include those, and you use them to move up and down in the filesystem hierarchy.

Something like grep { not /^.{1,2}\z/ } readdir HANDLE should work for you.