NSFileManager moveItem throws Error Code=513

Question

I'm trying to move a file from a URL to another, however I get an error with code 513. I understand that this is a NSFileWriteNoPermissionError. I don't see how this possible considering I created the folder in the first place.

//self.video!.folderURL.path = /var/mobile/Containers/Data/Application/066BDB03-FD47-48D8-B6F8-932AFB174DF7/Documents/AV/769c504203024bae95b47d78d8fe9029
try? fileManager.createDirectory(atPath: self.video!.folderURL.path, withIntermediateDirectories: true, attributes: nil)

// Update permission for AV folder
do {
     let parentDirectoryPath = self.video!.folderURL.deletingLastPathComponent().path
     let result = try fileManager.setAttributes([FileAttributeKey.posixPermissions: 0o777], ofItemAtPath: parentDirectoryPath)
        print(result)
     } catch {
        print("Error = \(error)")
     }

// sourceURL = file:///private/var/mobile/Containers/Data/PluginKitPlugin/50D8B8DB-19D3-4DD6-93DD-55F37CF87EA7/tmp/trim.6D37DFD2-5F27-4AB9-B478-5FED8AA6ABD7.MOV
// self.url = file:///var/mobile/Containers/Data/Application/066BDB03-FD47-48D8-B6F8-932AFB174DF7/Documents/AV/0b0b6803e891780850152eeab450a2ae.mov
do {
     try fileManager.moveItem(at: sourceURL, to: self.url)
   } catch {
     QLogTools.logError("Error moving video clip file \(error)")
   }

Error

Error Domain=NSCocoaErrorDomain Code=513 "“trim.90A10B33-B884-419F-BAD9-65583531C3C3.MOV” couldn’t be moved because you don’t have permission to access “AV”." UserInfo={NSSourceFilePathErrorKey=/private/var/mobile/Containers/Data/PluginKitPlugin/0849234B-837C-43ED-BEDD-DE4F79E7CE96/tmp/trim.90A10B33-B884-419F-BAD9-65583531C3C3.MOV, NSUserStringVariant=( Move

I tried altering the permission of the folder I created in the first place to 0o777, but when I print out its attributes it returns 511 as its permissions.

P.S:This only happens on iOS 13.

Answer 1

I solved my issue, but it may be different to what you were experiencing: I still had issues when changing to copyItem. I'm adding my findings here as an answer in case anyone else stumbles upon this question as I did and it helps them out.

My app loads custom files that can be downloaded from my website. With iOS 13's download manager, these are copied to the Downloads folder first, and can then be opened by my app. Yet my app was having permission errors when attempting to access these files in the same way as iOS 12.

This answer to a different question clued me in. I need to call startAccessingSecurityScopedResource() and stopAccessingSecurityScopedResource() as follows:

// source and destination are URLs
if source.startAccessingSecurityScopedResource() {
    try FileManager.default.moveItem(at: source, to: destination)
}
source.stopAccessingSecurityScopedResource()

The Apple documentation doesn't really suggest that this is new with iOS 13 but I think just the different approach to file downloading means sandboxing considerations need to be made.