Novell LINUX ENTERPRISE SERVER 10 - INSTALLATION AND ADMINISTRATION 08-05-2008 Installation Manual page 325

Before creating the directory, use the umask command to define which access permis-
sions should be masked each time a file object is created. The command umask 027
sets the default permissions by giving the owner the full range of permissions (0),
denying the group write access (2), and giving other users no permissions at all (7).
umask actually masks the corresponding permission bits or turns them off. For details,
consult the umask man page.
mkdir mydir creates the mydir directory with the default permissions as set by
umask. Use ls -dl mydir to check whether all permissions were assigned correctly.
The output for this example is:
drwxr-x--- ... tux project3 ... mydir
With getfacl mydir, check the initial state of the ACL. This gives information
like:
# file: mydir
# owner: tux
# group: project3
user::rwx
group::r-x
other::---
The first three output lines display the name, owner, and owning group of the directory.
The next three lines contain the three ACL entries owner, owning group, and other. In
fact, in the case of this minimum ACL, the getfacl command does not produce any
information you could not have obtained with ls.
Modify the ACL to assign read, write, and execute permissions to an additional user
geeko and an additional group mascots with:
setfacl -m user:geeko:rwx,group:mascots:rwx mydir
The option -m prompts setfacl to modify the existing ACL. The following argument
indicates the ACL entries to modify (multiple entries are separated by commas). The
final part specifies the name of the directory to which these modifications should be
applied. Use the getfacl command to take a look at the resulting ACL.
# file: mydir
# owner: tux
# group: project3
user::rwx
user:geeko:rwx
group::r-x
group:mascots:rwx
Access Control Lists in Linux 307