File System

It is possible to allow specific users to access specific directories within your home directory. You have hopefully already noticed the peculiar properties of the directories public and private. Any file or directory you store in public is readable by anyone and nothing in private is readable by anyone but yourself. This is achieved through the Access Control Lists (ACLs) for each directory. Each directory's ACL defines permissions for all files in that directory. Subsequent directories created in that directory will initially have the same permissions as their root directory. You can view the ACL of a directory with the command fs listacl. For example:

[bbadger@demo01] (1)$ fs listacl public

Access list for public is
Normal rights:
  system:administrators rlidwka
  system:anyuser rl
  bbadger rlidwka

Table: AFS permissions

Right		What it does
r	read	allow user to look at files in the directory
l	lookup	a user with this right may list a directory, look at an ACL or access subdirectories.
i	insert	allows user to add files to a directory.
d	delete	allows files to be removed by user.
w	write	allows files to be written and modified by user.
k	lock	allows advisory file locking.
a	administrator	allows user to change ACL. We do not advise giving other users the administrator right or removing your own administrator right.
shorthand notations for common combinations
all		rlidwka
write		rlidwk
read		rl
none		removes entry

Each of the characters on the right are abbreviations for the permissions summarized in figure 

To add an entry to an ACL, use the fs setacl command:

[bbadger@demo01] (1)$ fs setacl <directory> <user> <permissions>

For example, if the user ``bucky'' is your partner on an assignment you are working on in directory called 'project', you'd type

[bbadger@demo01] (1)$ fs setacl project bucky write