This blog post is for those who understand how file permissions work but are looking for an explanation on how file permissions behave when they are applied to directories. (but note that, without dir permission, one cannot still translate these names into inode numbers and hence, cannot reach the actual file/subdir) “ls -l” actually accesses the file info for which it needs access to its inode number and thus, it does not complete successfully unless exec permission on dir is available.