Modern versions of macOS use a file system permission model that’s far more complex than the traditional BSD rwx model, and this post is my attempt at explaining that model. If you have a question about this, post it here on DevForums. Put your thread in the App & System Services > Core OS topic area and tag it with Files and Storage. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" On File System Permissions Modern versions of macOS have four different file system permission mechanisms: Traditional BSD permissions Access control lists (ACLs) App Sandbox Mandatory access control (MAC) The first two were introduced a long time ago and rarely trip folks up. The second two are newer, more complex, and specific to macOS, and thus are the source of some confusion. This post is my attempt to clear that up. Error Codes App Sandbox and the mandatory access control system are both implemented using macOS’s sandboxing infrastructure. When a file system operation fails, check the error to see whether it was blocked by this sandboxing infrastructure. If an operation was blocked by BSD permissions or ACLs, it fails with EACCES (Permission denied, 13). If it was blocked by something else, it’ll fail with EPERM (Operation not permitted, 1). If you’re using Foundation’s FileManager, these error are both reported as Foundation errors, for example, the NSFileReadNoPermissionError error. To recover the underlying error, get the NSUnderlyingErrorKey property from the info dictionary. App Sandbox File system access within the App Sandbox is controlled by two factors. The first is the entitlements on the main executable. There are three relevant groups of entitlements: The com.apple.security.app-sandbox entitlement enables the App Sandbox. This denies access to all file system locations except those on a built-in allowlist (things like /System) or within the app’s containers. The various “standard location” entitlements extend the sandbox to include their corresponding locations. The various “file access temporary exceptions” entitlements extend the sandbox to include the items listed in the entitlement. Collectively this is known as your static sandbox. The second factor is dynamic sandbox extensions. The system issues these extensions to your sandbox based on user behaviour. For example, if the user selects a file in the open panel, the system issues a sandbox extension to your process so that it can access that file. The type of extension is determined by the main executable’s entitlements: com.apple.security.files.user-selected.read-only results in an extension that grants read-only access. com.apple.security.files.user-selected.read-write results in an extension that grants read/write access. Note There’s currently no way to get a dynamic sandbox extension that grants executable access. For all the gory details, see this post. These dynamic sandbox extensions are tied to your process; they go away when your process terminates. To maintain persistent access to an item, use a security-scoped bookmark. See Accessing files from the macOS App Sandbox. To pass access between processes, use an implicit security scoped bookmark, that is, a bookmark that was created without an explicit security scope (no .withSecurityScope flag) and without disabling the implicit security scope (no .withoutImplicitSecurityScope flag)). If you have access to a directory — regardless of whether that’s via an entitlement or a dynamic sandbox extension — then, in general, you have access to all items in the hierarchy rooted at that directory. This does not overrule the MAC protection discussed below. For example, if the user grants you access to ~/Library, that does not give you access to ~/Library/Mail because the latter is protected by MAC. Finally, the discussion above is focused on a new sandbox, the thing you get when you launch a sandboxed app from the Finder. If a sandboxed process starts a child process, that child process inherits its sandbox from its parent. For information on what happens in that case, see the Note box in Enabling App Sandbox Inheritance. IMPORTANT The child process inherits its parent process’s sandbox regardless of whether it has the com.apple.security.inherit entitlement. That entitlement exists primarily to act as a marker for App Review. App Review requires that all main executables have the com.apple.security.app-sandbox entitlement, and that entitlements starts a new sandbox by default. Thus, any helper tool inside your app needs the com.apple.security.inherit entitlement to trigger inheritance. However, if you’re not shipping on the Mac App Store you can leave off both of these entitlement and the helper process will inherit its parent’s sandbox just fine. The same applies if you run a built-in executable, like /bin/sh, as a child process. When the App Sandbox blocks something, it typically generates a sandbox violation report. For information on how to view these reports, see Discovering and diagnosing App Sandbox violations. To learn more about the App Sandbox, see the various links in App Sandbox Resources. For information about how to embed a helper tool in a sandboxed app, see Embedding a Command-Line Tool in a Sandboxed App. Mandatory Access Control Mandatory access control (MAC) has been a feature of macOS for many releases, but it’s become a lot more prominent since macOS 10.14. There are many flavours of MAC but the ones you’re most likely to encounter are: Full Disk Access (macOS 10.14 and later) Files and Folders (macOS 10.15 and later) App container protection (macOS 14 and later) App group container protection (macOS 15 and later) Data Vaults (see below) and other internal techniques used by various macOS subsystems Mandatory access control, as the name suggests, is mandatory; it’s not an opt-in like the App Sandbox. Rather, all processes on the system, including those running as root, as subject to MAC. Data Vaults are not a third-party developer opportunity. See this post if you’re curious. In the Full Disk Access and Files and Folders cases, users grant a program a MAC privilege using System Settings > Privacy & Security. Some MAC privileges are per user (Files and Folders) and some are system wide (Full Disk Access). If you’re not sure, run this simple test: On a Mac with two users, log in as user A and enable the MAC privilege for a program. Now log in as user B. Does the program have the privilege? If a process tries to access an item restricted by MAC, the system may prompt the user to grant it access there and then. For example, if an app tries to access the desktop, you’ll see an alert like this: “AAA” would like to access files in your Desktop folder. [Don’t Allow] [OK] To customise this message, set Files and Folders properties in your Info.plist. This system only displays this alert once. It remembers the user’s initial choice and returns the same result thereafter. This relies on your code having a stable code signing identity. If your code is unsigned, or signed ad hoc (“Signed to Run Locally” in Xcode parlance), the system can’t tell that version N+1 of your code is the same as version N, and thus you’ll encounter excessive prompts. Note For information about how that works, see TN3127 Inside Code Signing: Requirements. The Files and Folders prompts only show up if the process is running in a GUI login session. If not, the operation is allowed or denied based on existing information. If there’s no existing information, the operation is denied by default. For more information about app and app group container protection, see the links in Trusted Execution Resources. For more information about app groups in general, see App Groups: macOS vs iOS: Fight! On managed systems the site admin can use the com.apple.TCC.configuration-profile-policy payload to assign MAC privileges. For testing purposes you can reset parts of TCC using the tccutil command-line tool. For general information about that tool, see its man page. For a list of TCC service names, see the posts on this thread. Note TCC stands for transparency, consent, and control. It’s the subsystem within macOS that manages most of the privileges visible in System Settings > Privacy & Security. TCC has no API surface, but you see its name in various places, including the above-mentioned configuration profile payload and command-line tool, and the name of its accompanying daemon, tccd. While tccutil is an easy way to do basic TCC testing, the most reliable way to test TCC is in a VM, restoring to a fresh snapshot between each test. If you want to try this out, crib ideas from Testing a Notarised Product. The MAC privilege mechanism is heavily dependent on the concept of responsible code. For example, if an app contains a helper tool and the helper tool triggers a MAC prompt, we want: The app’s name and usage description to appear in the alert. The user’s decision to be recorded for the whole app, not that specific helper tool. That decision to show up in System Settings under the app’s name. For this to work the system must be able to tell that the app is the responsible code for the helper tool. The system has various heuristics to determine this and it works reasonably well in most cases. However, it’s possible to break this link. I haven’t fully research this but my experience is that this most often breaks when the child process does something ‘odd’ to break the link, such as trying to daemonise itself. If you’re building a launchd daemon or agent and you find that it’s not correctly attributed to your app, add the AssociatedBundleIdentifiers property to your launchd property list. See the launchd.plist man page for the details. Scripting MAC presents some serious challenges for scripting because scripts are run by interpreters and the system can’t distinguish file system operations done by the interpreter from those done by the script. For example, if you have a script that needs to manipulate files on your desktop, you wouldn’t want to give the interpreter that privilege because then any script could do that. The easiest solution to this problem is to package your script as a standalone program that MAC can use for its tracking. This may be easy or hard depending on the specific scripting environment. For example, AppleScript makes it easy to export a script as a signed app, but that’s not true for shell scripts. TCC and Main Executables TCC expects its bundled clients — apps, app extensions, and so on — to use a native main executable. That is, it expects the CFBundleExecutable property to be the name of a Mach-O executable. If your product uses a script as its main executable, you’re likely to encounter TCC problems. To resolve these, switch to using a Mach-O executable. For an example of how you might do that, see this post. Revision History 2024-11-08 Added info about app group container protection. Clarified that Data Vaults are just one example of the techniques used internally by macOS. Made other editorial changes. 2023-06-13 Replaced two obsolete links with links to shiny new official documentation: Accessing files from the macOS App Sandbox and Discovering and diagnosing App Sandbox violations. Added a short discussion of app container protection and a link to WWDC 2023 Session 10053 What’s new in privacy. 2023-04-07 Added a link to my post about executable permissions. Fixed a broken link. 2023-02-10 In TCC and Main Executables, added a link to my native trampoline code. Introduced the concept of an implicit security scoped bookmark. Introduced AssociatedBundleIdentifiers. Made other minor editorial changes. 2022-04-26 Added an explanation of the TCC initialism. Added a link to Viewing Sandbox Violation Reports.  Added the TCC and Main Executables section. Made significant editorial changes. 2022-01-10 Added a discussion of the file system hierarchy. 2021-04-26 First posted.

General: DevForums tags: Files and Storage, Finder Sync, File Provider, Disk Arbitration, APFS File System Programming Guide On File System Permissions DevForums post File Provider framework Finder Sync framework App Extension Programming Guide > App Extension Types > Finder Sync Disk Arbitration Programming Guide Mass Storage Device Driver Programming Guide Device File Access Guide for Storage Devices Apple File System Guide TN1150 HFS Plus Volume Format Extended Attributes and Zip Archives File system changes introduced in iOS 17 DevForums post Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com"

File system changes introduced in iOS 17 As part of iOS 17, tvOS 17, and watchOS 10, the system has reorganized where applications and their data containers are stored. In previous systems, both lived within the same volume but, starting in iOS 17, they will be stored on different volumes. What does this mean for you? Copying large amounts of data from the app bundle to a data container will take longer than in previous versions of iOS. Previously that copy would have occurred as an APFS file clone, but now the operation will occur as a standard copy, which may take much significantly longer. Because the data will need to be fully duplicated, storage usage will increase more than was the case in previous versions. You should minimize the data they copy out of their app bundle and avoid any unnecessary duplication of data between the app bundle and data container. When upgrading from previous system version, splitting the data into separate volumes may mean that there is insufficient space for all existing apps and their data. If this occurs, the app's data container will remain on the device, preserving the user's data, while the app bundle itself is removed using the same mechanism as "Offload Unused Apps". The user can then restore the app once they've freed sufficient space for the app to install. Revision History 2023-07-11 First posted

We have a seemingly randomly (and rarely) reproducible bug when a Microsoft Word (or Excel, Powerpoint...) temporary file with the ~$ prefix is not removed when the document is closed and causes a remotely deleted folder to be recreated via our file provider extension. We have received multiple issues from our users for some time now, and we could not reproduce it so far, but finally got a repro but could not identify the cause. We could reproduce it with the following steps, however not always, and only on one computer: We have the following file: FileProviderRoot/TEST/INSIDE/somefile.docx Open this file, edit with MS Word. A ~$mefile.docx hidden, temporary file is created next to the original file, while it is open in Word. This temp file is ignored by our file provider implementation by returning an .excludeFromSync error code. Save the file, modifications are synced. (don't know if this step is needed) We delete the container folder (FileProviderRoot/TEST/INSIDE) from within our app, the deletion change is propagated to the file provider, which in turn receives a call to createItem(basedOn:fields:contents:options:request:completionHandler:) that recreates the INSIDE folder, as - for some reason - the temp file cannot be deleted. Now we are stuck in this loop of delete/recreate until we go into the file provider folder and manually remove the stuck temp file. We would expect that the folder is not recreated but also removed from the file provider and disk along with the temp file. On the device that this issue was reproduced, it also seems to work correctly most of the time, but needs manual fixing when this issue occurs. We have a related bugreport: FB17928069

Hi All, I searched for this feedback but didn't see it, so apologies if this has been covered by another thread. Exploring the new camera app, It doesn't seem to recognize that external storage has been connected, so the additional features that allow ProRes high frame rates will throw an error dialog stating that "to use this you need external storage" even when external storage is connected. Using the Files app, the phone recognizes the storage, and this is something I can do with this external storage device on the previous version of IOS. It is clear that this release of the camera has been rewritten significantly since the last version. Is it possible that this is an oversight, a bug, or just functionality that has not been completed? Interested if anybody else is seeing this, or if it is just my setup.

I'm trying to make an FSKit module for NTFS read-write filesystem and at the stage where everything is more or less working fine as long as I mount the volume via mount -F and that volume is a RAM disk. However, since the default NTFS read-only driver is already present in macOS, this introduces an additional challenge. Judging by the DiskArbitration sources, it looks like all FSKit modules are allowed to probe anything only after all kext modules. So, in this situation, any third-party NTFS FSKit module is effectively blocked from using DiskArbitration mechanisms at all because it's always masked during the probing by the system's read-only kext. This leaves mount -F as the only means to mount the NTFS volume via FSKit. However, even that doesn't work for volumes on real (non-RAM) disks due to permission issues. The logs in Console.app hint that the FSKit extension is running; however, it looks like the fskitd itself doesn't have permissions to access real disks if it's initiated from the mount utility? default 16:42:41.939498+0200 fskitd New module list <private> default 16:42:41.939531+0200 fskitd Old modules (null) default 16:42:41.939578+0200 fskitd Added 2 identifiers: <private> default 16:42:41.939651+0200 fskitd [0x7fc58020bf00] activating connection: mach=true listener=true peer=false name=com.apple.filesystems.fskitd debug 16:42:41.939768+0200 fskitd main:RunLoopRun debug 16:42:41.939811+0200 fskitd -[liveFilesMountServiceDelegate listener:shouldAcceptNewConnection:]: start default 16:42:41.939870+0200 fskitd Incomming connection, entitled 0 debug 16:42:41.940021+0200 fskitd -[liveFilesMountServiceDelegate listener:shouldAcceptNewConnection:]: accepting connection default 16:42:41.940048+0200 fskitd [0x7fc580006120] activating connection: mach=false listener=false peer=true name=com.apple.filesystems.fskitd.peer[1816].0x7fc580006120 default 16:42:41.940325+0200 fskitd Hello FSClient! entitlement no default 16:42:41.940977+0200 fskitd About to get current agent for 503 default 16:42:41.941104+0200 fskitd [0x7fc580015480] activating connection: mach=true listener=false peer=false name=com.apple.fskit.fskit_agent info 16:42:41.941227+0200 fskitd About to call to fskit_agent debug 16:42:42.004630+0200 fskitd -[fskitdAgentManager currentExtensionForShortName:auditToken:replyHandler:]_block_invoke: Found extension for fsShortName (<private>) info 16:42:42.005409+0200 fskitd Probe starting on <private> debug 16:42:42.005480+0200 fskitd -[FSResourceManager getResourceState:]:not_found:<private> debug 16:42:42.005528+0200 fskitd -[FSResourceManager addTaskUUID:resource:]:<private>: Adding task (<private>) debug 16:42:42.005583+0200 fskitd applyResource starting with resource <private> kind 1 default 16:42:42.005609+0200 fskitd About to get current agent for 503 info 16:42:42.005629+0200 fskitd About to call to fskit_agent debug 16:42:42.006700+0200 fskitd -[fskitdXPCServer getExtensionModuleFromID:forToken:]_block_invoke: Found extension <private>, attrs <private> default 16:42:42.006829+0200 fskitd About to get current agent for 503 info 16:42:42.006858+0200 fskitd About to call to fskit_agent, bundle ID <private>, instanceUUID <private> default 16:42:42.070923+0200 fskitd About to grab assertion on pid 1820 default 16:42:42.071058+0200 fskitd Initializing connection default 16:42:42.071141+0200 fskitd Removing all cached process handles default 16:42:42.071185+0200 fskitd Sending handshake request attempt #1 to server default 16:42:42.071223+0200 fskitd Creating connection to com.apple.runningboard info 16:42:42.071224+0200 fskitd Acquiring assertion: <RBSAssertionDescriptor| "com.apple.extension.session" ID:(null) target:1820> default 16:42:42.071258+0200 fskitd [0x7fc58001cdc0] activating connection: mach=true listener=false peer=false name=com.apple.runningboard default 16:42:42.075617+0200 fskitd Handshake succeeded default 16:42:42.075660+0200 fskitd Identity resolved as osservice<com.apple.filesystems.fskitd> debug 16:42:42.076337+0200 fskitd Adding assertion 183-1817-1669 to dictionary debug 16:42:42.076385+0200 fskitd +[FSBlockDeviceResource(Project) openWithBSDName:writable:auditToken:replyHandler:]:bsdName:<private> default 16:42:42.076457+0200 fskitd [0x7fc5801092e0] activating connection: mach=true listener=false peer=false name=com.apple.fskit.fskit_helper default 16:42:42.077706+0200 fskitd +[FSBlockDeviceResource(Project) openWithBSDName:writable:auditToken:replyHandler:]_block_invoke: Open device returned error Error Domain=NSPOSIXErrorDomain Code=13 info 16:42:42.077760+0200 fskitd +[FSBlockDeviceResource(Project) openWithBSDName:writable:auditToken:replyHandler:]: failed to open device <private>, Error Domain=NSPOSIXErrorDomain Code=13 default 16:42:42.077805+0200 fskitd [0x7fc5801092e0] invalidated because the current process cancelled the connection by calling xpc_connection_cancel() debug 16:42:42.077830+0200 fskitd +[FSBlockDeviceResource(Project) openWithBSDName:writable:auditToken:replyHandler:]:end info 16:42:42.078459+0200 fskitd openWith returned err Error Domain=NSPOSIXErrorDomain Code=13 dev (null) error 16:42:42.078501+0200 fskitd -[fskitdXPCServer getRealResource:auditToken:reply:]: Unable to convert proxy FSBlockDeviceResource into open resource error 16:42:42.078538+0200 fskitd -[fskitdXPCServer applyResource:targetBundle:instanceID:initiatorAuditToken:authorizingAuditToken:isProbe:usingBlock:]: Can't get the real resource of <private> default 16:42:42.105443+0200 fskitd [0x7fc580006120] invalidated because the client process (pid 1816) either cancelled the connection or exited The mount utility call I use is the same for RAM and real disks with the only difference being the device argument and this permission error is only relevant for real disks case. So, the proper solution (using DiskArbitration) seems to be blocked architecturally in this use case due to FSKit modules being relegated to the fallback role. Is this subject to change in the future? The remaining workaround with using the mount directly doesn't work for unclear reasons. Is that permission error a bug? Or am I missing something?

I see this in Tahoe Beta release notes macOS now supports the Apple Sparse Image Format (ASIF). These space-efficient images can be created with the diskutil image command-line tool or the Disk Utility application and are suitable for various uses, including as a backing store for virtual machines storage via the Virtualization framework. See VZDiskImageStorageDeviceAttachment. (152040832) I'm developing a macOS app using the Virtualization framework and need to create disk images in the ASIF (Apple Sparse Image Format) to make use of the new feature in Tahoe Is there an official way to create/resize ASIF images programmatically using Swift? I couldn’t find any public API that supports this directly. Any guidance or recommendations would be appreciated. Thanks!

Hello everyone, I'm developing a macOS application that programmatically sets custom icons for folders, and I've hit a wall trying to get Finder to display the icon changes consistently. The Goal: To change a folder's icon using NSWorkspace.shared.setIcon and have Finder immediately show the new icon. What I've Tried (The Refresh Mechanism): After setting the icon, I attempt to force a Finder refresh using several sandbox-friendly techniques: Updating the Modification Date (the "touch" method): try FileManager.default.setAttributes([.modificationDate: Date()], ofItemAtPath: pathToUse) Notifying NSWorkspace: NSWorkspace.shared.noteFileSystemChanged(pathToUse) Posting Distributed Notifications: DistributedNotificationCenter.default().post(name: Notification.Name("com.apple.Finder.FolderChanged"), object: pathToUse) The Problem: This combination of methods works perfectly, but only under specific conditions: When setting a custom icon on a folder for the first time. When changing the icon of an alias. For any subsequent icon change on a regular folder, Finder stubbornly displays the old, cached icon. I've confirmed that the user can see the new icon by manually closing and reopening the folder window, but this is obviously not a user-friendly solution. Investigating a Reset with AppleScript: I've noticed that the AppleScript update command seems to force the kind of complete refresh I need: tell application "Finder" update POSIX file "/path/to/your/folder" end tell Running this seems to reset the folder's state in Finder, effectively recreating the "first-time set" scenario where my other methods work. However, the major roadblock is that I can't figure out how to reliably execute this from a sandboxed environment. I understand it likely requires specific scripting entitlements, but it's unclear which ones would be needed for this update command on a user-chosen folder, or if it's even permissible for the App Store. My Questions: Is there a reliable, sandbox-safe way to make the standard Cocoa methods (noteFileSystemChanged, updating the modification date, etc.) work for subsequent icon updates on regular folders? Am I missing a step? If not, what is the correct way to configure a sandboxed app's entitlements to safely run the tell application "Finder" to update command for a folder the user has granted access to? Any insight or alternative approaches would be greatly appreciated. Thank you

I am developing an Apple app that has to download 1000s of MP4 files between 5 and 150MB each at one time (can take an hour or more - is OK). I use Apple's file picker to select the files, and then it freezes and I cannot download anything. I had this working a few months ago but now I cannot get it to work. Can someone give me some advice please?

We are seeing a kernel panic in nfsd when using vagrant synced folders. The issue started with macOS 15.4 and still occurs with macOS 15.5. It’s 100% reproducible when bringing up a new vagrant environment. The kernel panic does not occur when using smb instead of nfs. https://developer.hashicorp.com/vagrant/docs/synced-folders/nfs Other people have reported a similar issue when using nfs with Docker. https://github.com/docker/for-mac/issues/7664 I filed this under FB17853906. I spoke with an engineer at the Apps &amp; Services WWDC lab and they recommended I post here to make sure the bug gets looked at and routed to the correct team.

I've gotten to the point where I can use the mount(8) command line tool and the -t option to mount a file system using my FSKit file system extension, in which case I can see a process for my extension launch, probe, and perform the other necessary actions. However, when plugging in my USB flash drive or trying to mount with diskutil mount, the file system does not mount: $ diskutil mount disk20s3 Volume on disk20s3 failed to mount If you think the volume is supported but damaged, try the "readOnly" option $ diskutil mount readOnly disk20s3 Volume on disk20s3 failed to mount If you think the volume is supported but damaged, try the "readOnly" option Initially I thought it would be enough to just implement probeExtension(resource:replyHandler:) and the system would handle the rest, but this doesn't seem to be the case. Even a trivial implementation that always returns .usable doesn't cause the system to use my FSModule, even though I've enabled my extension in System Settings > General > Login Items & Extensions > File System Extensions. From looking at some of the open source msdos and Disk Arb code, it seems like my app extension needs to list FSMediaTypes to probe. I eventually tried putting this in my Info.plist of the app extension: <key>FSMediaTypes</key> <dict> <key>EBD0A0A2-B9E5-4433-87C0-68B6B72699C7</key> <dict> <key>FSMediaProperties</key> <dict> <key>Content Hint</key> <string>EBD0A0A2-B9E5-4433-87C0-68B6B72699C7</string> <key>Leaf</key> <true/> </dict> </dict> <key>0FC63DAF-8483-4772-8E79-3D69D8477DE4</key> <dict> <key>FSMediaProperties</key> <dict> <key>Content Hint</key> <string>0FC63DAF-8483-4772-8E79-3D69D8477DE4</string> <key>Leaf</key> <true/> </dict> </dict> <key>Whole</key> <dict> <key>FSMediaProperties</key> <dict> <key>Leaf</key> <true/> <key>Whole</key> <true/> </dict> </dict> <key>ext4</key> <dict> <key>FSMediaProperties</key> <dict> <key>Content Hint</key> <string>ext4</string> <key>Leaf</key> <true/> </dict> </dict> </dict> </plist> (For reference, the partition represented by disk20s3 has a Content Hint of 0FC63DAF-8483-4772-8E79-3D69D8477DE4 and Leaf is True which I verified using IORegistryExplorer.app from the Xcode additional tools.) Looking in Console it does appear now that the system is trying to use my module (ExtendFS_fskit) to probe when I plug in my USB drive, but I never see a process for my extension actually launch when trying to attach to it from Xcode by name (unlike when I use mount(8), where I can do this). However I do see a Can't find the extension for <private> error which I'm not sure is related but does sound like the system can't find the extension for some reason. The below messages are when filtering for "FSKit": default 19:14:53.455826-0400 diskarbitrationd probed disk, id = /dev/disk20s3, with ExtendFS_fskit, ongoing. default 19:14:53.456038-0400 fskitd Incomming connection, entitled 1 default 19:14:53.456064-0400 fskitd [0x7d4172e40] activating connection: mach=false listener=false peer=true name=com.apple.filesystems.fskitd.peer[350].0x7d4172e40 default 19:14:53.456123-0400 fskitd Hello FSClient! entitlement yes default 19:14:53.455902-0400 diskarbitrationd [0x7461d8dc0] activating connection: mach=true listener=false peer=false name=com.apple.filesystems.fskitd default 19:14:53.456151-0400 diskarbitrationd Setting remote protocol to all XPC default 19:14:53.456398-0400 fskitd About to get current agent for 501 default 19:14:53.457185-0400 diskarbitrationd probed disk, id = /dev/disk20s3, with ExtendFS_fskit, failure. error 19:14:53.456963-0400 fskitd -[fskitdXPCServer applyResource:targetBundle:instanceID:initiatorAuditToken:authorizingAuditToken:isProbe:usingBlock:]: Can't find the extension for <private> (I only see these messages after plugging my USB drive in. When running diskutil mount, I see no messages in the console when filtering by FSKit, diskarbitrationd, or ExtendFS afterward. It just fails.) Is there a step I'm missing to get this to work, or would this be an FSKit bug/current limitation?

In my app the user can select a source folder to be synced with a destination folder. The sync can also happen in response to a change in the source folder detected with FSEventStreamCreate. If the user unzips an archive in the source folder and the sync process begins before the unzip operation has completed, the sync can fail because of a "Permission denied" error. I assume this is related to the posix permissions of the extracted folder being 420 during the unzip operation and (in my case) 511 afterwards. Is there a way to detect than an unzip operation is in progress and wait until it has completed? I thought that using NSFileCoordinator would solve this issue, but unfortunately it's not the case. Since an unzip operation can last any amount of time, it's not ideal to just delay a sync by a fixed number of seconds and let the user deal with any error if the unzip operation takes longer. let openPanel = NSOpenPanel() openPanel.canChooseDirectories = true if openPanel.runModal() == .cancel { return } let url = openPanel.urls[0].appendingPathComponent("extracted", isDirectory: false) var error: NSError? NSFileCoordinator(filePresenter: nil).coordinate(readingItemAt: url, error: &error) { url in do { print(try FileManager.default.attributesOfItem(atPath: url.path).sorted(by: { $0.key.rawValue < $1.key.rawValue }).map({ ($0.key.rawValue, $0.value) })) try FileManager.default.contentsOfDirectory(at: url, includingPropertiesForKeys: nil) } catch { print(error) } } if let error = error { print("file coordinator error:", error) }

We are experimenting with FileProvider on MacOS, we want to set ACL policy restriction on a folder and the same policy needs to be applied down to its children. To achieve this currently we are setting corresponding NSFileProviderItemCapabilities on parent folder and recursively iterate over all of its children and set the capability on each individual child items. GOAL: We expect the root's ACL policy to be implicitly percolated down to its children without explicitly being iterated over them and setting it individually. From our research, we couldn't find any policy that can help us achieve the above goal. If there are any such provisions in FileProvider, please guide us to them.

I'm working on a build system similar to Bazel where each build action runs in a sandbox. The sandbox contains only the files that the user defined as input to ensure that the build action doesn't have any implicit dependencies. Bazel achieves this by creating a "symlink forest" to the original source files. This works, but I have observed fseventsd using significant CPU during a Bazel build, presumably because of all the symlinks that get created. Is there a way to disable file events for a directory or a volume? The "File System Events Programming Guide" in the Documentation Archive mentions placing an empty file named no_log in the .fseventsd directory at the root of the volume, but when testing on macOS 15.5 with APFS that appears to no longer work. Related, is a "symlink forest" the best way to create a sandbox like this? Or is there a different method one can use to provide a view of a subset of the files in a directory tree? I read up on the App Sandbox but that seems too coarse grained. Something like Linux's overlayfs would work well, and maybe one can achieve a similar functionality with firmlinks? Curious about folks thoughts here. Thanks in advance!

I am developing a background application that acts as a metadata server under MacOS written in Swift. Sandboxed clients prompt the user to select URLs which are passed to the server as security scoped bookmarks via an App Group and the metadata will be passed back. I don't want the I/O overhead of passing the complete image file data to the server. All the variations I have tried of creating security scoped bookmarks in the client and reading them from the server fail with error messages such as "The file couldn’t be opened because it isn’t in the correct format." Can anyone guide me in the right direction or is this just not possible?

The URL directory obtained by UIDocumentPickerVieweController can be read and written in the directory after calling startAccessingDecurityScopeResource. However, after restarting the app, if the URL saved in the package is called startAccessingDecurityScopeResource again and returns NO, UIDocumentPickerVieweController must be called again to retrieve the URL, and then startAccessingDecurityScopeResource must be called again before continuing the operation. This is too troublesome. Is there a way to continue reading and writing operations in the URL directory after restarting the app?

Hi all, I have repeatedly the issue that a certain .strings file in my app's bundle has the extended files attribute com.apple.quarantine set. Consequently the submission fails with the following mail notification: We noticed one or more issues with a recent delivery for the following app: [...] ITMS-91109: Invalid package contents - The package contains one or more files with the com.apple.quarantine extended file attribute, such as “abcdef.strings”. This attribute isn’t permitted in macOS apps distributed on TestFlight or the App Store. Please remove the attribute from all files within your app and upload again. I'm able to resubmit the bundle after cleaning the file attribute via xattr -d -r com.apple.quarantine..., but the funny thing is it happens again and again - on a .strings file which hasn't been downloaded (but manually created), shouldn't be under Gatekeeper's quarantine, and wasn't edited in the meantime. Is anybody else observing the same issue with macOS 15.4.1, Xcode 16.3? Greetings, Matthias

Will the ES_EVENT_TYPE_NOTIFY_OPEN event be called back when the user has already returned es_respond_flags_result(client, msg, 0, false) in ES_EVENT_TYPE_AUTH_OPEN? I believe the ES_EVENT_TYPE_NOTIFY_OPEN event should not be triggered if the user has already denied the open operation in the ES_EVENT_TYPE_AUTH_OPEN response handler. However, during my testing, ES_EVENT_TYPE_NOTIFY_OPEN was still being called even after I blocked the open process. Is this behavior correct?

Hello everyone, I’m working on an iOS app that uses the new DeviceActivity framework to monitor and report user screen‐time in an extension (DeviceActivityReportExtension). I need to persist my processed screen‐time data into a standalone SQLite database inside the extension, but I’m running into issues opening and writing to the database file. Here’s what I’ve tried so far: import UIKit import DeviceActivity import SQLite3 class DeviceActivityReportExtension: DeviceActivityReportExtension { private var db: OpaquePointer? override func didReceive(_ report: DeviceActivityReport) async { // 1. Construct path in app container: let containerURL = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.com.mycompany.myapp") let dbURL = containerURL?.appendingPathComponent("ScreenTimeReports.db") // 2. Open database: if sqlite3_open(dbURL?.path, &amp;db) != SQLITE_OK { print("❌ Unable to open database at \(dbURL?.path ?? "unknown path")") return } defer { sqlite3_close(db) } // 3. Create table if needed: let createSQL = """ CREATE TABLE IF NOT EXISTS reports ( id INTEGER PRIMARY KEY AUTOINCREMENT, date TEXT, totalScreenTime DOUBLE ); """ if sqlite3_exec(db, createSQL, nil, nil, nil) != SQLITE_OK { print("❌ Could not create table: \(String(cString: sqlite3_errmsg(db)))") return } // 4. Insert data: let insertSQL = "INSERT INTO reports (date, totalScreenTime) VALUES (?, ?);" var stmt: OpaquePointer? if sqlite3_prepare_v2(db, insertSQL, -1, &amp;stmt, nil) == SQLITE_OK { sqlite3_bind_text(stmt, 1, report.date.description, -1, nil) sqlite3_bind_double(stmt, 2, report.totalActivityDuration) if sqlite3_step(stmt) != SQLITE_DONE { print("❌ Insert failed: \(String(cString: sqlite3_errmsg(db)))") } } sqlite3_finalize(stmt) } } However: Path issues: The extension’s sandbox is separate from the app’s. I’m not sure if I can use the same App Group container, or if there’s a better location for an on‐extension database. Entitlements: I’ve added the App Group (group.com.mycompany.myapp) to both the main app and the extension, but the file never appears, and I still get “unable to open database” errors. My questions are: How do I correctly construct a file URL for an SQLite file in a DeviceActivityReportExtension? Is SQLite the recommended approach here, or is there a more “Apple-approved” pattern for writing data from a DeviceActivity extension? Any sample code snippets, pointers to relevant Apple documentation, or alternative approaches would be greatly appreciated!

How do I gain access to the Documents folder? Under targets, "signing and capabilities", App Sandbox, I can see the Music folder, Desktop... but not Documents.

I found the live activity process cannot write to the app group and FileManger, can only read the app group. When I write using FileManager in a live activity process, the console prompts me with a permission error. When I write using UserDefault(suit:) in the live activity process, I read a null value in the main app. Is this the case for real-time event design? I haven’t seen any documentation mentioning this. Does anyone know, thank you very much.

Hi All, I am looking for a terminal command to get the exact same output as the file count you recieve when using Get Info in finder. The closest i can get is using the find command with flags: find 'path/to/folder' -not -path '*/\.*' -and -not -path '*\.key/*' -and -not -path '*\.numbers/*' -and -not -path '*\.pages/*' -and -not -path '*__MACOSX/*' -and -not -path '*\.pdf/*' -and -not -path '*\.app/*' -and -not -path '*\.rtfd/*' | wc -l I will be searching on an external volume that sometimes produces keynote save files that finder sometimes sees as a package and sometimes sees as a folder. If a folder finder counts the items contained if a package it doesn't, I need the command or script to mimic this behaviour. In the example of the screenshot get info on the top folder produces a count of 14 and the find command produces a count of 23. There are also other behaviours that differ the file count between them but i'm not sure what causes them. Any help on a solution it being a command or script would be much apreciated. Thanks, James

Recently, some feedback has been received. After users upgrade to ipados 17.7.7 and return to the login status and restart the App, it will become invalid. We checked the log and found that the content stored in NSUserdefault would be lost after restarting the App. Has anyone encountered this problem?