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How detect cyclic symbolic links using NSFileManager?
My code is crashing Xcode (or even macOS kernel) during debugging - Xcode just vanishes from screen! // pseudo code public func hunt(in directory: URL) { let fileIterator = fileMan.enumerator(at: directory) // collect app packages into a list var packages = [URL]() for case let fileURL as URL in fileIterator { if fileURL.pathExtension == "app" { packages.append(fileURL) } } // FileWrappers var wrappers = [FileWrappers]() for packageURL in packages { //!!! The line below eventually crashes Xcode (or even macOS kernel once)! wrappers[packageURL] = try? FileWrapper(url: packageURL, options: .immediate) // NOTE: I need FileWrapper.matchesContents later in some code } } // unit test case func test() {} myObj.hunt(in: URL(fileURLWithPath: "/Applications")) } I suspect that the FileWrapper constructor is traversing directories and encounter cyclic symbolic links and eventually it crashes; since it's running at system runtime level, most probably it also crashes macOS kernel! So my question is that is there any way to detect cyclic symbolic links so that I can design my own logics similar to FileWrapper?
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435
Jan ’24
Where is help on Swift documentation markup?
I am reluctant to admit that I only came to know that Swift provides a builtin documentation markup syntax just a few months ago. /** Test func Some description here. - Parameters: - b:Test - d: Test - f: Test - Returns: Bool */ func myMethod(a b:Int, c d:Int, e f:Int) -> Bool { b > d } It seems the markup is pretty simple and has only a few keywords. But, I want to read through the complete reference. Any useful pointers?
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822
Dec ’23
GridView addRow height problem
I am trying to add rows to GridView and not able to get expected row height correctly. override func viewDidLoad() { super.viewDidLoad() // Remove the row in IB designer gridView.removeRow(at: 0) let image = NSImage(named: NSImage.colorPanelName)! //image.size = NSMakeSize(80, 80) let imageView = NSImageView(image: image) imageView.imageFrameStyle = .grayBezel imageView.imageScaling = .scaleAxesIndependently imageView.frame = NSMakeRect(0, 0, 80, 80) let label = NSTextField(labelWithString: "test text") let row = gridView.addRow(with: [imageView, label]) row.height = 80 } What was wrong with my code?
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781
Dec ’23
Environment variable not working in another user account
I have the following in my .zshrc: export MY_LIBRARY_DIR=~/bin In Xcode I can set header/lib search path using something like $(MY_LIBRARY_DIR)/abc. This works fine in my daily used user account. But today I found that this technique does not work in a test user account (for testing purpose only). I even reboot my machine but still can't get it working. Am I missing something very obvious??? BTW, I am using Xcode 14.2 and 14.3.1.
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576
Dec ’23
How read image file metadata?
I want to read metadata of image files such as copyright, author etc. I did a web search and the closest thing is CGImageSourceCopyPropertiesAtIndex: - (void)tableViewSelectionDidChange:(NSNotification *)notif { NSDictionary* metadata = [[NSDictionary alloc] init]; //get selected item NSString* rowData = [fileList objectAtIndex:[tblFileList selectedRow]]; //set path to file selected NSString* filePath = [NSString stringWithFormat:@"%@/%@", objPath, rowData]; //declare a file manager NSFileManager* fileManager = [[NSFileManager alloc] init]; //check to see if the file exists if ([fileManager fileExistsAtPath:filePath] == YES) { //escape all the garbage in the string NSString *percentEscapedString = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL, (CFStringRef)filePath, NULL, NULL, kCFStringEncodingUTF8); //convert path to NSURL NSURL* filePathURL = [[NSURL alloc] initFileURLWithPath:percentEscapedString]; NSError* error; NSLog(@"%@", [filePathURL checkResourceIsReachableAndReturnError:error]); //declare a cg source reference CGImageSourceRef sourceRef; //set the cg source references to the image by passign its url path sourceRef = CGImageSourceCreateWithURL((CFURLRef)filePathURL, NULL); //set a dictionary with the image metadata from the source reference metadata = (NSDictionary *)CGImageSourceCopyPropertiesAtIndex(sourceRef,0,NULL); NSLog(@"%@", metadata); [filePathURL release]; } else { [self showAlert:@"I cannot find this file."]; } [fileManager release]; } Is there any better or easy approach than this?
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783
Dec ’23
What should I do with UTI (NSImage.imageTypes)?
Per the docs, NSImage.imageTypes returns a list UTI's, something like below: com.adobe.pdf com.apple.pict com.adobe.encapsulated-postscript public.jpeg public.png com.compuserve.gif com.canon.tif-raw-image ... What I need is get file extensions of a UTI. For example, public.jpeg picture file may have several file extensions, say .jpg,.jpeg,.jfif. Does Cocoa provide any API to query for this information?
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765
Nov ’23
Weird problem of NSTableView with auto layout
I have had this issue for a long time. If I configure any auto layout constraints in TableViewCell, I get extremely weird layout behavior in IB designer; however, layout is completely good during runtime. For example, with a completely new project and a single NSTableView on the main view, I get: If I resize main view, the tableview won't get resized Every time I reopen the project, the tableview would shrink by height. It seems the shrinked height is doubled every time. For example, in the following screenshot, the gap is 56. Next reopen will double the gap to 112. Is this a known bug? I would want to file bug report at https://feedbackassistant.apple.com.
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Nov ’23