Linux ACL permission

  /acl/dir                                     →                             touch test permission

  user:: rwx                         file  default permission 666   rw-

 group:: r-x                          dir  default permission 777

 other:: r-x

 default:user:: rwx                   default permission  rw-                         user:: rw-

 default:other:: r-x                   default permission  rw-                         other:: r--

 default:mask:: rwx                  default permission  rw-                         mask:: rw-

                                                                 rwx

 default:user:john: rwx               修正後  ACL mask   rw-  →     rw-    →   user:john: rw-  

                                                                -------

                                                                 rw-

                                                                  

                                                                 r-x

 default:group:: r-x                  修正後  ACL mask   rw-  →     rw-    →     group:: r--

                                                                ------

                                                                 r--