New ACP/Xfile Utility: ACL

Controlling access control lists.

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CROYDON (Rixstep) — Rixstep announce the new file management utility ACL available immediately to all ACP and Xfile subscribers.

ACL is the ACP access control list utility. It manages access control lists on Apple's OS X.

Access control lists are an alternate (and more granular) way of controlling access to file system objects. Apple get this technology through their adaptation of the FreeBSD group who in turn seem inspired by Dave Cutler's work on NT Server.



The difference is Unix already has a fully adequate file permissions system and Microsoft Windows has none.

This has of course led to innumerable unpleasant surprises and setbacks for unfortunate users of Microsoft Windows. Access control lists on Unix systems such as FreeBSD and Apple's OS X may instead be seen as an enhancement - a little extra icing on the cake.

But there's no getting around the fact they're intended primarily for use by administrators on the server end.

Apple have their own comparable utility for OS X Server but feedback from admins on this product led to the creation of ACL. The permissions system is streamlined - Unix won't distinguish between files and directories, the API in use doesn't either, so there's no reason to beat about the bush here as well.



ACL's basic layout uses five columns of data in the upper view, all related to file system security. All security fields are accessible and modifiable through the standard ACP framework info sheet.

It's likely - and even recommended - that ordinary users (even ACP/Xfile users) exercise caution when experimenting with ACLs: having multiple potentially conflicting methods of controlling file system access can get them into a quagmire.

But ACL is a necessary utility especially for those occasions when they're already presented with such a quagmire and have to find their way out.

ACL for OS X 10.6 is available for free to all ACP and Xfile subscribers as of 1 March 2011.