화일 모드에 관해서 질문이요

$ man chmod
...
       The letters `rwxXstugo' select the new permissions for the
       affected users: read (r), write (w),  execute  (or  access
       for directories) (x), execute only if the file is a direc­
       tory or already has execute permission for some user  (X),
       set  user  or  group  ID on execution (s), sticky (t), the
       permissions that the user who owns the file currently  has
       for it (u), the permissions that other users in the file's
       group have for it (g),  and  the  permissions  that  other
       users not in the file's group have for it (o).
...