Editing File-system permissions (section)

{{Use American English|date=January 2019}}
{{Short description|Technology for controlling access to file system items}}

Typically, a [[file system]] maintains '''permission''' settings for each stored item {{endash}} commonly [[computer file|files]] and [[directory (computer)|directories]] {{endash}} that either grant or deny the ability to manipulate file system items. Often the settings allow controlling access based on function such as read, change, navigate, and [[Execution (computing)|execute]] and to different [[computer user|users]] and groups of users. One well-established technology was developed for [[Unix]] and later codified by [[POSIX]]. Another common technology is an [[access-control list]] (ACL) with multiple variants implemented in file systems and one codified by POSIX. Since POSIX defines both the older Unix-based technology as well as ACLs, the former is called ''traditional POSIX permissions'' for clarity even though it is not a well-known term.

A [[permission-driven user interface]] tailors the functionality available to the user based on file system item permissions. For example, the interface might hide menu options that are not allowed based on the permissions stored for an item.