How to Modify ACL Entries on a File

1. Modify ACL entries on a file by using the setfacl command.

   $ setfacl -m acl_entry_list filename1 [filename2 ...]

   -m	Modifies the existing ACL entry.
   acl_entry_list	Specifies the list of one or more ACL entries to modify on the file or directory. You can also modify default ACL entries on a directory. Table 17-8 and Table 17-9 show the valid ACL entries.
   filename ...	Specifies one or more files or directories.

2. To verify that the ACL entries were modified on the file, use the getfacl command.

   $ getfacl filename

Examples--Modifying ACL Entries on a File

The following example modifies the permissions for the user george to read/write.

$ setfacl -m user:george:6 ch3.doc
$ getfacl ch3.doc
# file: ch3.doc
# owner: nathan
# group: staff
user::rw-				
user::george:rw-				#effective:r--
group::r-	              #effective:r--
mask:r--
other:r-

The following example modifies the default permissions for the group staff to read and the default ACL mask permissions to read/write on the book directory.

$ setfacl -m default:group:staff:4,default:mask:6 book