Entrepreneurs and venture capitalists are setting up firms across the Pacific, only to find that any investment with Chinese ties is a hard sell.

The kernel at the heart of macOS is XNU, standing for X is Not Unix, as, however much macOS might have in common with Unix, once you scratch its surface it’s all very different. Several of you commented recently that what I referred to as a user’s UniqueID should have been termed User ID as it would be in Unix. But dig deeper and you’ll see that macOS does indeed refer to that internally as the UniqueID, because that’s how it’s named for Directory Services in macOS.

Older versions of macOS used to provide advanced options for users in Users & Groups settings, where you could even change a user’s UUID. Then a bright spark thought it would be fun to tell users to change that in a misguided bid to improve their privacy. When someone who seems to know what they’re writing about tells you to do that, you go and try it, don’t you? Only changing a user’s UUID is catastrophic, and most who did so ended up having to rebuild the contents of their Mac from scratch to put the damage right. The lesson is that you should never try anything you don’t understand, for which there’s no simple undo, and which might have serious side-effects. Please don’t do that: it’s such a crazy idea that it’s malicious in intent. As a result, Apple has progressively removed those dangerous advanced user settings, to keep them out of harm’s way.

But there are times when you do need to make such changes, or at least check what current settings are. For those you’ll need Directory Services’ editor, Directory Utility, which is carefully hidden in /System/Library/CoreServices/Applications. Whatever you do, please don’t authenticate to Directory Utility, to ensure that you can’t inadvertently change anything that could give you grief.

Modern Directory Services have a long history that I’ll explain on Saturday morning, but they’re basically descended from NeXTSTEP’s NetInfo and the Lightweight Directory Access Protocol (LDAP) implemented in Apple’s successor Open Directory. These flourished in the days of Mac OS X Server, but since then have carried on quietly serving macOS with information about users, groups, and a whole lot more.

Directory Utility may be hidden away, but it’s still well documented, and its Help book is worth browsing. Unless your Mac is connected to a server delivering it LDAPv3, Active Directory or similar services, once you’ve selected the Directory Editor at the top, view Users in the node /Local/Default, as your Mac’s local directory. There you’ll find your personal details, including your UUID as GeneratedUID, your Home folder as NFSHomeDirectory, long user name as RealName, short name as RecordName, and user ID as UniqueID.

Listed as users are many of the services your Mac connects to on your behalf, including the App Store, Apple Pay, Find My and more. Each of these has its own UniqueID, PrimaryGroupID, and more. There may also be hidden users that you thought had been removed, and shared folders from years ago. Don’t give way to any temptation to try ‘cleaning’ this up, as it’s all too easy to wreak havoc unintentionally.

In the past, Directory Utility was commonly used to enable the root user and change its password, features that may still available today in its Edit menu once you’ve authenticated. At one time this was useful, but shouldn’t be used any more unless you’re advised to by Apple.

Directory Utility is now mainly used when integrating a Mac with a network directory server, including Open Directory (formerly in Mac OS X Server), LDAP on a Linux or other server, and Microsoft’s Active Directory. For the advanced user it gathers important information in one place, and every once in a blue moon it can unscramble a Mac or user account that would otherwise require starting from scratch. But please don’t authenticate and start making changes, as you’ll most likely regret it.

Sometimes developing software is a journey of exploration without a clear destination. A couple of weeks ago, I wrote about how log entries from Battery Center revealed useful information about input devices like keyboards and mice, and Uninterruptible Power Supplies (UPS). Several of you remarked that it would be useful to have a utility to provide easy access to those. This is my first progress report, and comes complete with a first version of that utility, Unhidden.

Battery Center

It turns out that those log entries from the com.apple.BatteryCenter don’t come from macOS itself, but from one of three new Private Frameworks added to macOS Sonoma: BatteryCenter itself, and two supporting frameworks BatteryCenterUI and BatteryUIKit. In Ventura and earlier, similar log entries came from com.apple.iohid, although those weren’t as extensive.

Battery Center appears to support Battery widgets in /System/Library/CoreServices/Batteries.app named BatteriesAvocadoWidget, and offered in Sonoma’s new range of widgets.

Thus, com.apple.BatteryCenter periodically checks known connected input devices (‘HID’ for Human Interface Devices), UPS, and internal batteries in Mac notebooks, and publishes lists of information in the log. That data is used by the background service app Batteries.app to feed the data displayed in the Battery widgets available in Sonoma.

Unless your Mac has a Battery widget installed, perhaps on its Desktop, Battery Center entries don’t appear in its log. When you do add a Battery widget to the Desktop, though, checks are made every few seconds, and their results written to the log, and those continue even after removing the widget, at least until the next time that Mac is shut down or restarted.

Third-party software isn’t supposed to access private services like Battery Center, so creating an independent utility to perform similar functions would have to capture its own data. However, given access to the log, it’s possible to read Battery Center’s entries there instead.

Unhidden

This initial version does one job: each time you open a new window in the app, it displays the most recent results obtained by Battery Center, across all the devices that it checks. There are three essential requirements:

• The Mac must be running macOS Sonoma or later (including Sequoia betas); this works on both Intel and Apple silicon Macs.
• The user must have admin privileges, as those are required to access the log.
• Battery Center must be running. This normally requires that a Battery widget has been installed since the last time that Mac started up, unless it’s already running.

Each time Unhidden opens a fresh window, it inspects the log for Battery Center entries. It initially checks the last 5 seconds, then increases the time period up to a maximum of half an hour. It then either reports that it can’t find any entries from Battery Center, or it displays them in the window.

Standard display gives all key results obtained in compact lines. If those aren’t clear or large enough, there’s optional Large Text.

Supported devices

Unhidden has been tested with the following:

• Apple wireless Magic Keyboards, both operating on battery and when connected by their charging cable
• Apple wireless Magic Mice, both operating on battery and when connected by their charging cable
• Apple wireless Magic Trackpad 2, both operating on battery and when connected by their charging cable
• Supported UPS connected by a USB cable
• Standard Mac notebook internal batteries, both charging and not.

The range of peripherals is wide, and to make it easy to report problems with other devices, and errors, Unhidden has a Debug Mode. To enter that, it must be selected in Settings, the app quit, and opened again. Instead of seeing normal results in its window, Debug Mode displays the original raw log entries, together with a button to save those in a text file. Please add problem entries to this article as comments, or send them to me by email (address in the About page), so that Unhidden can accommodate more devices correctly.

Download

Unhidden version 1.0 is now available only from here for the time being: unhidden01

Future

I’d really like to discover a way of activating Battery Center without having to fiddle with widgets, something I’ll be looking at next. There are several alternative ways to present these results, and to check them at regular intervals, perhaps presenting changes graphically. Please let me know where you’d like Unhidden to go, if you’re interested in my developing it any further.