BSD 文件属性 ll

The file mode printed under the -l option consists of the entry type and
     the permissions.  The entry type character describes the type of file, as
     follows:

           -     Regular file.
           b     Block special file.
           c     Character special file.
           d     Directory.
           l     Symbolic link.
           p     FIFO.
           s     Socket.

           w     Whiteout.

  1b  bbb bbb bbb

-/b/c rwx rwx rwx 

文件类型/所属用户具有的读写权限/所属用户所在组具有的权限/其它用户的权限

user(用户)，group(组)和other(其它)