18.0 Access Control Lists in Linux
POSIX ACLs (access control lists) can be used as an expansion of the
traditional permission concept for file system objects. With ACLs,
permissions can be defined more flexibly than the traditional permission
concept allows.
The term POSIX ACL suggests that this is a true POSIX
(portable operating system interface) standard. The
respective draft standards POSIX 1003.1e and POSIX 1003.2c have been
withdrawn for several reasons. Nevertheless, ACLs as found on many systems
belonging to the UNIX family are based on these drafts and the
implementation of file system ACLs as described in this chapter follows
these two standards as well. They can be viewed at
https://wt.xpilot.org/publications/posix.1e/.
