OSLog is a unified logging system for the reading of historical data.

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Collect logs from OSLog during app background transition cause crash
We use OSLog to log message in our iOS app and retrieve logs to save into local file when app goes to background. This way we will be able to persist logs after app terminated. However, when logs become large, retrieving logs takes more than 5 seconds during background transition that cause our app being killed by the system with below info: Exception Type: EXC_CRASH (SIGKILL) Exception Codes: 0x0000000000000000, 0x0000000000000000 Termination Reason: FRONTBOARD 2343432205 <RBSTerminateContext| domain:10 code:0x8BADF00D explanation:scene-update watchdog transgression: app<com.cisco.secureclient.zta(B7AB7300-8A17-4C71-88BC-BA3D55AF6666)>:1261 exhausted real (wall clock) time allowance of 10.00 seconds ProcessVisibility: Background ProcessState: Running WatchdogEvent: scene-update WatchdogVisibility: Background WatchdogCPUStatistics: ( "Elapsed total CPU time (seconds): 13.500 (user 10.890, system 2.610), 21% CPU", "Elapsed application CPU time (seconds): 2.119, 3% CPU" ) reportType:CrashLog maxTerminationResistance:Interactive> Triggered by Thread: 0 Thread 0 name: Dispatch queue: com.apple.main-thread Thread 0 Crashed: 0 libsystem_kernel.dylib 0x1ed6e01d8 mach_msg2_trap + 8 1 libsystem_kernel.dylib 0x1ed6dff70 mach_msg2_internal + 80 2 libsystem_kernel.dylib 0x1ed6dfe88 mach_msg_overwrite + 436 3 libsystem_kernel.dylib 0x1ed6dfcc8 mach_msg + 24 4 libdispatch.dylib 0x1aea4df00 _dispatch_mach_send_and_wait_for_reply + 540 5 libdispatch.dylib 0x1aea4e2a0 dispatch_mach_send_with_result_and_wait_for_reply + 60 6 libxpc.dylib 0x20fd406d0 xpc_connection_send_message_with_reply_sync + 264 7 Foundation 0x1a5ad96c0 NSXPCCONNECTION_IS_WAITING_FOR_A_SYNCHRONOUS_REPLY + 16 8 Foundation 0x1a5ac13bc -[NSXPCConnection _sendInvocation:orArguments:count:methodSignature:selector:withProxy:] + 2160 9 Foundation 0x1a5aec6cc -[NSXPCConnection _sendSelector:withProxy:arg1:] + 116 10 Foundation 0x1a5aec604 _NSXPCDistantObjectSimpleMessageSend1 + 60 11 OSLog 0x1f4b98118 -[OSLogCurrentProcessEnumerator nextObject] + 192 12 libswiftOSLog.dylib 0x213983270 OSLogStore.PrivateIterator.next() + 32 13 libswiftOSLog.dylib 0x213983324 protocol witness for IteratorProtocol.next() in conformance OSLogStore.PrivateIterator + 28 14 libswiftCore.dylib 0x1a0050ed0 _IteratorBox.next() + 108 15 MyApp 0x104359e28 static MyLogger.getFormattedLogs() (in MyApp ) (MyLogger.swift:63) + 122408 Here is our code to retrieve logs: struct MyLogger { public var log: Logger init(subsystem: String = getSubsystem(), file: String = #file, function: String = #function, line: Int = #line, context: String = "myapp") { let category = "\(context): \(file): \(line): \(function): " log = Logger(subsystem: subsystem, category: category) } static func getFormattedLogs() -> [String] { do { // Combine log message with timestamp and category with // file/line/function information let df = DateFormatter() df.dateFormat = ZtaConstants.DATE_FORMAT let store = try OSLogStore.init(scope: .currentProcessIdentifier) let logEntries = try store.getEntries() .compactMap{ $0 as? OSLogEntryLog} .filter { $0.subsystem.contains(getSubsystem() } .map{df.string(from: $0.date) + " " + String(format:"0x%02x", $0.threadIdentifier) + " " + String(format:"0x%x", $0.activityIdentifier) + " " + String($0.processIdentifier) + " " + $0.category + " " + $0.composedMessage} return formattedLogs } catch let err { ZtaLogger().log.error("Failed to collect log: \(err)") return [] } } } It looks like getFormattedLogs() takes long time because we use filter to get message that logged by our app and format the log entry. Since compactMap is O(m+n) complexity, filter and map are O(n) that cause performance issue. Is there a better way to get logs from our app via OSLog? Could retrieving logs be called in appDidEnterBackground()? Thanks, Ying
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600
Feb ’24
System logging messages disappear after about 90 seconds
I'm having an issue with logging on my system (Sonoma 14.3.1), in that log messages disappear after 60-90 seconds, despite logging being configured to persist. This seems to happen across all subsystems. The symptoms are: • Watching the log stream in Console.app, messages older than 60-90 seconds disappear, even if no new messages are coming in. • log show --last 2d only returns messages from the last couple of minutes. I've filed FB13616761, but wondered if anyone had any other insights or suggestions. TIA
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448
Feb ’24
iOS: Can OSLogPreferences applied to Xcode console?
I'm trying to figure out how to maximize the value of structured logging in my project. The log filtering improvements in Xcode 15 are great but limited to being able to control the logging at a fine-grained level. For example, if I want to always disable some chatty debug logs for a specific category. Setting OSLogPreference solves this problem once you've installed it onto a device, but when running in debug mode on Xcode, it seems to ignore this and print everything. Is there a way to apply OSLogPreference while running Xcode, or another way to selectively disable categories?
4
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740
Jan ’24
Cannot switch log level to off?
What do I miss here? root@MacBook-Pro /tmp # sw_vers ProductName: macOS ProductVersion: 13.6.1 BuildVersion: 22G313 root@MacBook-Pro /tmp # log config --mode "level: off" root@MacBook-Pro /tmp # log config --status System mode = INFO root@MacBook-Pro /tmp # log config --mode "level: debug" root@MacBook-Pro /tmp # log config --status System mode = DEBUG root@MacBook-Pro /tmp # log config --mode "level: off" root@MacBook-Pro /tmp # log config --status System mode = DEBUG
2
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562
Jan ’24
Can I access system logs from Swift (I want logs for previous runs of my application)
Hi folks, For accessing the logs, I’m using OSLogStore object. I want to be able to read logs from any previous run of my application. I can of course do this: // Open the log store. var logStore = try OSLogStore(scope: .currentProcessIdentifier) But this only allows me to retrieve logs from my current running process. I can also do this: // Open the log store. var logStore = try OSLogStore(scope: .system) But this only works if my App Sandbox entitlement is false. I tried disabling the sandbox, and I was able to get to all the logs (which is good) but according to this page: https://developer.apple.com/documentation/security/app_sandbox/ it says: To distribute a macOS app through the Mac App Store, you must enable the App Sandbox capability Since we are planning on distributing our app on the store, this presents a big problem for me. (I didn't try submitting to TestFlight to see if it's really the case). I don’t know if there are exclusions or ways around this – I don’t see an entitlement that I can add which would allow access to the logs. Does anyone know a way around this? Thanks, David
2
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735
Jan ’24
/usr/bin/log sometimes does not work through NSTask
Our application (which happens to run in an admin account, thus there's no problem authenticating) collects logs calling /usr/bin/log through NSTask. Usually this works all right, but sometimes all we get is the header Timestamp Thread Type Activity PID TTL and nothing else. The tool finishes with a zero result code, we get nothing on stderr and just the header above on stdout, with a proper EOF (as determined by a zero-length availableData read from an NSFileHandle through the stdout pipe). At the same moment, if the /usr/bin/log tool is run manually in a Terminal window with precisely the same arguments in the same user account the application runs in, we get the logs all right. Any idea what might be the culprit and how to fix the problem? Thanks!
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489
Jan ’24
os_log wrapper crashed when using "%s"
I am trying to wrap os_log for logging in my iOS app like so: import Foundation import OSLog enum LogCategory: String, CaseIterable { case viewCycle case tracking case api } struct Log { private static let logs = { return LogCategory.allCases .reduce(into: [LogCategory: OSLog]()) { dict, category in dict[category] = OSLog(subsystem: Bundle.main.bundleIdentifier ?? "BIMB", category: category.rawValue) } }() static func debug(category: LogCategory, message: StaticString, _ args: CVarArg...) { logImpl(category: category, message: message, type: .debug, args) } static func info(category: LogCategory, message: StaticString, _ args: CVarArg...) { logImpl(category: category, message: message, type: .info, args) } static func notice(category: LogCategory, message: StaticString, _ args: CVarArg...) { logImpl(category: category, message: message, type: .default, args) } static func warning(category: LogCategory, message: StaticString, _ args: CVarArg...) { logImpl(category: category, message: message, type: .default, args) } static func error(category: LogCategory, message: StaticString, _ args: CVarArg...) { logImpl(category: category, message: message, type: .error, args) } static func critical(category: LogCategory, message: StaticString, _ args: CVarArg...) { logImpl(category: category, message: message, type: .fault, args) } private static func logImpl(category: LogCategory, message: StaticString, type: OSLogType, _ args: CVarArg...) { guard let log = logs[category] else { return } os_log(message, log: log, type: type, args) } } The problem is if I did this: Log.debug(category: .tracking, message: "Device ID: %s.", UIDevice.current.identifierForVendor?.uuidString ?? "unknown") it always crashed with this error: 2023-12-13 12:33:35.173798+0700 bimb-authenticate-ios[62740:928633] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[Swift.__SwiftDeferredNSArray UTF8String]: unrecognized selector sent to instance 0x600000dcbbc0' But if I just do it with os_log like this: os_log("Device ID: %s.", log: OSLog(subsystem: Bundle.main.bundleIdentifier!, category: "tracking"), type: .debug, UIDevice.current.identifierForVendor?.uuidString ?? "unknown") it worked fine. Also if I changed %@ in my wrapper instead, it didn't crash, but the idfv is shown inside a pair of brackets like this: Device ID: ( "C0F906C8-CD73-44F6-86A1-A587248680D3" ).` But with os_log it is shown normally like this: Device ID: C0F906C8-CD73-44F6-86A1-A587248680D3. Can you tell me what's wrong here? And how do I fix this? Thanks. NOTE: This is using os_log since the minimum version is iOS 11. I don't know why people advising me with using Logger instead.
1
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547
Dec ’23
OSLog Line Numbers & Source File Only Shown On Mouse Hover in Tiny Text?
For awhile I've wrapped OSLog in my own macros to include the line number and source file the logging statement originates from in debug mode because OSLog didn't include that info in console output (until recently). Now I noticed the source code file and line number of the logging statement isn't being shown (I have all the metadata switches turned on in Xcode's console "Metadata Options" popover). Then I realized it is being shown, only on mouse hover over the logging statement in very tiny text. The text is barely readable (on mouse hover). Why would viewing the line number require me to move the mouse cursor over a logging statement? It doesn't look pretty at all (hiding information behind mouse hover) and even if it did look pretty, this is the console for programmers and we don't care about such nonsense.
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652
Dec ’23
NSLog unreliable in Xcode 15 Console
I'm finding that in Xcode 15, NSLog statements (from Objective-C, in this case) will sometimes appear in Xcode's Console and sometimes will not. This is making it difficult to debug using our existing logging, which for our REST API requests and responses has been working well for about ten years and is a tough thing to lose. Is there any way I can restore reliable handling of NSLog in Xcode 15's Console without having to rewrite all (over 200) of our uses of NSLog to use OSLog? Note: I am aware that Xcode 15's Console sometimes takes more than 30 seconds to start tracking app output, but it appears that in some cases the content of individual NSLog statements never will appear. (If this 30 second delay is news to anyone, it may be related to a spam of identical warnings that are okay which occur on launch of our app. I have suspected that Xcode 15 just gets a bit flustered with identical messages and gives up for a bit.) Thank you!
6
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1.7k
Dec ’23
How to disable dimming on the screen, and print os_log on the content screen
I have created an iOS .ipa file to run some tests, and all the test cases have os_log implemented for tracing. However, there is an issue; my tests take over 20 seconds to run, and the screen starts to dim. Consequently, the execution stops. Once I reactivate the screen, the tests resume. I added [UIApplication.sharedApplication setIdleTimerDisabled:YES]; to the code, but it doesn't resolve the problem. I've used os_log to trace all the test case results. I wonder if it's possible to display all the os_log messages from runTest on the app main screen as well. int main(int argc, char** argv) { //Separate thread to runTest, os_log implemented there std::thread thread_obj(runTests, argc, argv); int applicationReturn; @autoreleasepool { [UIApplication.sharedApplication setIdleTimerDisabled:YES]; applicationReturn = UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class])); } thread_obj.join(); [UIApplication.sharedApplication setIdleTimerDisabled:NO]; return applicationReturn; }
3
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505
Nov ’23
os_log private not shown in Ventura
Lately, I've switched from NSLog to the new os_log. My problem is, whatever I try, I can't see the private values in my 13.6 (22G120). My test line is trivial os_log(OS_LOG_DEFAULT,"private shown: %@", [NSString stringWithFormat:@"OK"]); and it prints (both in Xcode and in Console) private shown: <private> I did install in Settings the appropriate profile (as found here, copied down, changed just my company info) — in vain, it did not help, not even after restarting my computer. For the record, the profile is shown below. Can anybody see what am I doing wrong and why it does not work? Thanks! <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>ConsentText</key> <dict> <key>default</key> <string>This will enable showing private strings and data in Unified Logs.</string> </dict> <key>PayloadContent</key> <array> <dict> <key>PayloadDisplayName</key> <string>ManagedClient logging</string> <key>PayloadEnabled</key> <true/> <key>PayloadIdentifier</key> <string>com.apple.system.logging.89AE58D8-0A4A-448B-8AE0-761DEE2D007F</string> <key>PayloadType</key> <string>com.apple.system.logging</string> <key>PayloadUUID</key> <string>89AE58D8-0A4A-448B-8AE0-761DEE2D007F</string> <key>PayloadVersion</key> <integer>1</integer> <key>System</key> <dict> <key>Enable-Private-Data</key> <true/> </dict> </dict> </array> <key>PayloadDescription</key> <string>Allows showing private log messages.</string> <key>PayloadDisplayName</key> <string>Allow Private Logs</string> <key>PayloadIdentifier</key> <string>cz.ocs.enable.private.logs</string> <key>PayloadOrganization</key> <string>OCSoftware</string> <key>PayloadRemovalDisallowed</key> <false/> <key>PayloadType</key> <string>Configuration</string> <key>PayloadUUID</key> <string>529DF49A-6CB3-4DE9-A29F-4C41EC88BFDD</string> <key>PayloadVersion</key> <integer>1</integer> </dict> </plist>
4
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772
Nov ’23
Exporting from OSLogStore doesn't respect privacy.
When exporting OSLog entries from OSLogStore, composedMessage doesn't seem to respect the given privacy marker. This feels like a bug to me, but it maybe a case of me holding it wrong. Here's an example: import UIKit import OSLog class ViewController: UIViewController { let logger = Logger(subsystem: "com.example.project", category: "ViewController") override func viewDidLoad() { super.viewDidLoad() logger.info("Top secret number \(42, privacy: .private)") do { let store = try OSLogStore(scope: .currentProcessIdentifier) let postion = store.position(timeIntervalSinceLatestBoot: 1) let logs = try store.getEntries(at: postion) .compactMap { $0 as? OSLogEntryLog } .filter { $0.subsystem == "com.example.project" } .map { $0.composedMessage } // Prints: // Logger: ["Top secret number 42"] print("Logger: \(logs)") } catch { print(error) } } } Is there a more appropriate way to format the text ready for sharing?
2
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555
Nov ’23
NSLog no longer sh
I use a macro to do logging: #define LOG(fmt, ...) NSLog((fmt), ##VA_ARGS); which means I can write code like: LOG(@"radius=%.1f", fRadius) Up until Xcode 15 the %.1f would be respected and display fRadius to one decimal place. But since Xcode 15 it seems to ignore that and just display all decimal places regardless. Anyone know why, and how to fix that?
4
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542
Nov ’23
Can I use OSLogStore to access logs from earlier runs of my app?
I understand that in iOS 15 and macOS Monterey, I can easily access the log system to get log entries for my app like this: let store = try OSLogStore(scope: .currentProcessIdentifier) I can then query store for the log entries. However, as it says right in the name, the store is only for current process, i.e current run of my app. When I try to get entries, I only get entries from the current run, even if I specify an earlier time like this: guard let positionDate = Calendar.current.date(byAdding: .day, value: -7, to: Date()) else { return } let position = store.position(date: positionDate) let predicate = NSPredicate(format: "subsystem == 'com.exampl.emyAppSubsystem'") let entries = try store.getEntries(with: [], at: position, matching: predicate) for entry in entries { print("Entry: \(entry.date) \(entry.composedMessage)") } Is there any way to access log entries for earlier runs of my app, e.g from days or weeks ago? Either on macOS or iOS?
7
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3.4k
Nov ’23
Silencing OS subsystem signposts on iOS
Environment Context: iOS 17.0 Simulator Xcode 15.0 In the above environment, I'm noticing in Instruments that the OS subsystem com.apple.VectorKit is emitting os_signpost events at a rate of ~2.8 events/ms. This large amount of data logging seems to be triggering warnings of: 'Data stream: 1 log/signpost messages lost due to high rates' ...when trying to capture other system logging data. (In the attached screenshot, notice the warning sign icons right outside the selected time series.) This is preventing me from being able to successfully log my own signpost data and profile my application. As well, this subsystem's data is unnecessary for my purposes and distracting. I have tried to disable logging for this subsystem in the Simulator by running the following from the macOS host: % xcrun simctl spawn booted log config --subsystem com.apple.VectorKit --mode level:off ...and confirmed it with: % xcrun simctl spawn booted log config --subsystem com.apple.VectorKit --status Mode for 'com.apple.VectorKit' OFF PERSIST_OFF ...however, when running Instruments after the above output, this data does not actually get disabled. How can I disable this subsystem's logging? Feedback Assistant report: FB13292000
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522
Oct ’23
Your Friend the System Log
The unified system log on Apple platforms gets a lot of stick for being ‘too verbose’. I understand that perspective: If you’re used to a traditional Unix-y system log, you might expect to learn something about an issue by manually looking through the log, and the unified system log is way too chatty for that. However, that’s a small price to pay for all its other benefits. This post is my attempt to explain those benefits, broken up into a series of short bullets. Hopefully, by the end, you’ll understand why I’m best friends with the system log, and why you should be too! If you have questions or comments about this, start a new thread and tag it with OSLog so that I see it. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" Your Friend the System Log Apple’s unified system log is very powerful. If you’re writing code for any Apple platform, and especially if you’re working on low-level code, it pays to become friends with the system log! The Benefits of Having a Such Good Friend The public API for logging is fast and full-featured. And it’s particularly nice in Swift. Logging is fast enough to leave log points [1] enabled in your release build, which makes it easier to debug issues that only show up in the field. The system log is used extensively by the OS itself, allowing you to correlate your log entries with the internal state of the system. Log entries persist for a long time, allowing you to investigate an issue that originated well before you noticed it. Log entries are classified by subsystem, category, and type. Each type has a default disposition, which determines whether that log entry is enable and, if it is, whether it persists in the log store. You can customise this, based on the subsystem, category, and type, in four different ways: Install a configuration profile created by Apple (all platforms). Add an OSLogPreferences property to your app’s Info.plist (all platforms). Run the log tool with the config command (macOS only) Create and install a custom configuration profile with the com.apple.system.logging payload (macOS only). When you log a value, you may tag it as private. These values are omitted from the log by default but you can configure the system to include them. For information on how to do that, see Recording Private Data in the System Log. The Console app displays the system log. On the left, select either your local Mac or an attached iOS device. Console can open and work with log snapshots (.logarchive). It also supports surprisingly sophisticated searching. For instructions on how to set up your search, choose Help > Console Help. Console’s search field supports copy and paste. For example, to set up a search for the subsystem com.foo.bar, paste subsystem:com.foo.bar into the field. Console supports saved searches. Again, Console Help has the details. Console supports viewing log entries in a specific timeframe. By default it shows the last 5 minutes. To change this, select an item in the Showing popup menu in the pane divider. If you have a specific time range of interest, select Custom, enter that range, and click Apply. Instruments has os_log and os_signpost instruments that record log entries in your trace. Use this to correlate the output of other instruments with log points in your code. Instruments can also import a log snapshot. Drop a .logarchive file on to Instruments and it’ll import the log into a trace document, then analyse the log with Instruments’ many cool features. The log command-line tool lets you do all of this and more from Terminal. There’s a public API to read back existing log entries, albeit one with significant limitations on iOS (more on that below). Every sysdiagnose log includes a snapshot of the system log, which is ideal for debugging hard-to-reproduce problems. For more details on that, see Using a Sysdiagnose Log to Debug a Hard-to-Reproduce Problem. For general information about sysdiagnose logs, see Bug Reporting > Profiles and Logs. But you don’t have to use sysdiagnose logs. To create a quick snapshot of the system log, run the log tool with the collect subcommand. If you’re investigating recent events, use the --last argument to limit its scope. For example, the following creates a snapshot of log entries from the last 5 minutes: % sudo log collect --last 5m For more information, see: os > Logging OSLog log man page os_log man page (in section 3) os_log man page (in section 5) WWDC 2016 Session 721 Unified Logging and Activity Tracing [1] Well, most log points. If you’re logging thousands of entries per second, the very small overhead for these disabled log points add up. Foster Your Friendship Good friendships take some work on your part, and your friendship with the system log is no exception. Follow these suggestions for getting the most out of the system log. The system log has many friends, and it tries to love them the all equally. Don’t abuse that by logging too much. One key benefit of the system log is that log entries persist for a long time, allowing you to debug issues with their roots in the distant past. But there’s a trade off here: The more you log, the shorter the log window, and the harder it is to debug such problems. Put some thought into your subsystem and category choices. One trick here is to use the same category across multiple subsystems, allowing you to track issues as they cross between subsystems in your product. Or use one subsystem with multiple categories, so you can search on the subsystem to see all your logging and then focus on specific categories when you need to. Don’t use too many unique subsystem and context pairs. As a rough guide: One is fine, ten is OK, 100 is too much. Choose your log types wisely. The documentation for each OSLogType value describes the default behaviour of that value; use that information to guide your choices. Remember that disabled log points have a very low cost. It’s fine to leave chatty logging in your product if it’s disabled by default. No Friend Is Perfect The system log API is hard to wrap. The system log is so efficient because it’s deeply integrated with the compiler. If you wrap the system log API, you undermine that efficiency. For example, a wrapper like this is very inefficient: -*-*-*-*-*- DO NOT DO THIS -*-*-*-*-*- void myLog(const char * format, ...) { va_list ap; va_start(ap, format); char * str = NULL; vasprintf(&str, format, ap); os_log_debug(sLog, "%s", str); free(str); va_end(ap); } -*-*-*-*-*- DO NOT DO THIS -*-*-*-*-*- This is mostly an issue with the C API, because the modern Swift API is nice enough that you rarely need to wrap it. If you do wrap the C API, use a macro and have that pass the arguments through to the underlying os_log_xyz macro. iOS has very limited facilities for reading the system log. Currently, an iOS app can only read entries created by that specific process, using .currentProcessIdentifier scope. This is annoying if, say, the app crashed and you want to know what it was doing before the crash. What you need is a way to get all log entries written by your app (r. 57880434). There are two known bugs with the .currentProcessIdentifier scope. The first is that the .reverse option doesn’t work (r. 87622922). You always get log entries in forward order. The second is that the getEntries(with:at:matching:) method doesn’t honour its position argument (r. 87416514). You always get all available log entries. Xcode 15 beta has a shiny new console interface. For the details, watch WWDC 2023 Session 10226 Debug with structured logging. For some other notes about this change, search the Xcode 15 Beta Release Notes for 109380695. In older versions of Xcode the console pane was not a system log client (r. 32863680). Rather, it just collected and displayed stdout and stderr from your process. This approach had a number of consequences: The system log does not, by default, log to stderr. Xcode enabled this by setting an environment variable, OS_ACTIVITY_DT_MODE. The existence and behaviour of this environment variable is an implementation detail and not something that you should rely on. Xcode sets this environment variable when you run your program from Xcode (Product > Run). It can’t set it when you attach to a running process (Debug > Attach to Process). Xcode’s Console pane does not support the sophisticated filtering you’d expect in a system log client. When I can’t use Xcode 15, I work around the last two by ignoring the console pane and instead running Console and viewing my log entries there. If you don’t see the expected log entries in Console, make sure that you have Action > Include Info Messages and Action > Include Debug Messages enabled. The system log interface is available within the kernel but it has some serious limitations. Here’s the ones that I’m aware of: This is no subsystem or category support )-: There is no support for annotations like {public} and {private}. Adding such annotations causes the log entry to be dropped (r. 40636781). Revision History 2023-10-20 Added some Instruments tidbits. 2023-10-13 Described a second known bug with the .currentProcessIdentifier scope. Added a link to Using a Sysdiagnose Log to Debug a Hard-to-Reproduce Problem. 2023-08-28 Described a known bug with the .reverse option in .currentProcessIdentifier scope. 2023-06-12 Added a call-out to the Xcode 15 Beta Release Notes. 2023-06-06 Updated to reference WWDC 2023 Session 10226. Added some notes about the kernel’s system log support. 2023-03-22 Made some minor editorial changes. 2023-03-13 Reworked the Xcode discussion to mention OS_ACTIVITY_DT_MODE. 2022-10-26 Called out the Showing popup in Console and the --last argument to log collect. 2022-10-06 Added a link WWDC 2016 Session 721 Unified Logging and Activity Tracing. 2022-08-19 Add a link to Recording Private Data in the System Log. 2022-08-11 Added a bunch of hints and tips. 2022-06-23 Added the Foster Your Friendship section. Made other editorial changes. 2022-05-12 First posted.
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0
5.9k
Oct ’23
Console app not showing info and debug logs
I have a Swift 3 Cocoa application that uses Apple's Unified Logging, like this: - import os class MyClass { @available(OSX 10.12, *) static let scribe = OSLog(subsystem: "com.mycompany.myapp", category: "myapp") func SomeFunction(){ if #available(OSX 10.12, *){ os_log("Test Error Message", log: MyClass.scribe, type: .error) } if #available(OSX 10.12, *){ os_log("Test Info Message", log: MyClass.scribe, type: .info) } if #available(OSX 10.12, *){ os_log("Test Debug Message", log: MyClass.scribe, type: .debug) } } }Within the Console application, both Include Info Messages and Include Debug Messages are turned on.When os_log is called, only the error type message is visible in the Console application.Using Terminal, with the command, all message types are visible in the Terminal output: -sudo log stream --level debugI've tried running the Console app as root, via sudo from the command line and the same issue occurs; no debug or info messages can be seen, even though they're set to being turned on under the Action menu.Setting system-wide logging to be debug, has no effect on the Console application output:sudo log config --mode level:debugPlease can someone tell me what I'm missing and how can I view debug and info messages in the Console application?
29
0
33k
Oct ’23
os_log crashing in MacOS 14 Sonoma
minimum is to create an os_log once in the parent, then, after fork, use an existing os_log instance or create a new one. Here's my reproduction sample. It looks like an OS bug, So what is the workaround till its solved and releases. #include <os/log.h> #include <stdio.h> #include <errno.h> #define USE_SWIFT_LOGGER 0 // set to 1 to use Logger() instead of os_log() #define USE_SHARED_LOG 0 // set to 1 to use a shared os_log instance instead of allocating one for each os_log() call #if USE_SWIFT_LOGGER // log messages using Swift's Logger class instead of calling os_log_... directly #include "forktest-Swift.h" #define LOG(msg) log_using_logger([NSString stringWithUTF8String:msg]) const char * logMethod = "Swift's Logger"; #elif USE_SHARED_LOG // use a shared os_log instance for all log messages static os_log_t log = os_log_create("com.ivanti.forktest", "foo"); #define LOG(msg) os_log_debug(log, msg) const char * logMethod = "shared log"; #else // create a new os_log instance for each log message #define LOG(msg) os_log_debug(os_log_create("com.ivanti.forktest", "foo"), msg) const char * logMethod = "new log instance for each message"; #endif static void forkTest() { int pid = fork(); if (pid < 0) { fprintf(stderr, "fork failed: %s\n", strerror(errno)); exit(1); } else if (pid == 0) { printf("in child process...\n"); LOG("in child process..."); printf("child process done\n"); } else { printf("child process pid: %d\n", pid); } } int main(int arc, const char ** argv) { printf("Log method: %s\n", logMethod); LOG("entering main..."); forkTest(); LOG("leaving main..."); return 0; }
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Oct ’23