Introduction

What are ACLs and why would you want to use them?

ACLs are Access Control Lists for files and directories. They are based on the IEEE's POSIX 1003.1e draft 17, also known simply as POSIX.1e.   ACLs are an addition to the standard Unix file permissions (r,w,x,-) for User, Group, and Other. ACLs give users and administrators flexibility and fine-grained control over who can read, write, and execute files. This can all be done without adding mysterious groups and pestering the system administrator.

Commercial Unix operating systems (except SCO) have all had ACL functionality for quite awhile. Microsoft's NTFS also has similar capabilities. FreeBSD 5.x supports POSIX.1e ACLs as well. The new Linux 2.6 kernel supports ACLs for EXT2, EXT3, XFS, JFS, and ReiserFS.

Fedora Core 2, Red Hat's first distribution with a 2.6 kernel, is a good vehicle for taking Linux ACLs for a test drive. This document is a basic HOWTO/tutorial on using ACLs with Fedora.