This post is meant to clarify a few key concepts about Unix filesystems such as directory permissions, hardlinks and symlinks.

If you need to identify broken symlinks, you can do the following :
find -L . -type l

The -L options instructs find to follow symlinks when possible. Hence no “working symlink” will ever get returned as the targets won’t match -type l (meaning “file is a symlink”).

On the other hand, find will not be able to follow broken symlinks, so the information will be taken from the symlink itself and not from the non-existent or otherwise unreachable target. The -type l will then be a match and the broken symlink filename will be returned.