OS/File/System/Directory

• File system directory

  • In the POSIX sense, a directory is a special file whose content is a sequence of directory entries (struct dirent), each mapping a name to an OS/File/System/Inode number within the same file system.
  • The directory does not store file content or most metadata — those live in the inode. It is purely a name-to-inode mapping.
  • Every directory contains two automatic OS/File/System/Link/Hards: . (pointing to itself) and .. (pointing to the parent directory).

  • Contrast with the colloquial sense

    • In everyday use, "directory" and "folder" are synonyms for a container that organizes files.
    • In the POSIX data-structure sense, a directory is the mechanism that gives a file its name: the name lives in the directory entry, not in the file itself.