Question

The purpose of the access control lists regarding files and directories

Answer 1

· A list of permissions associated with an object is called as Access Control List.

· An ACL specifies which users or system processes are granted access to objects.

· An ACL specifies what operations are allowed on given objects.

· You can also say, it contains rules that grant or deny access to certain digital environments.

· They are tools for managing permissions within a file system.

· They give users and groups read, write, and/or execute permissions on files or directories.

· Each object has a security attribute.

· This security attribute identifies its access control list.

· The list has an entry for each system user with access permissions.

· UNIX file protection provides read, write, and execute permissions for the three user classes.

· The three user classes are file owner, file group, and other.

· An access control list (ACL) gives best file security by enabling to do the following:

· For file owner, the group, other, specific users and groups file permissions are defined

· Default permissions for each of the preceding categories are defined

· Example

· If you want all the people in a group to be able to read file, you can grant group read permissions on that file.

· Now, if you want only one person in the group to be able to write to that file.

· File security is not provided by the Standard UNIX.

· However, an ACL provides this level of file security.