iOS: How do you find the creation date of a file?

Question

I'm trying to find the creation date (NOT modification date) of a file.

Creation date doesn't appear to be in the attributes of a file, though modified date is.

I'm using this code..

NSFileManager* fm = [NSFileManager defaultManager];

NSString* path = [PathHelpers pathInDocumentsFolderWithFilename:FILE_NAME];
NSDictionary* attrs = [fm attributesOfItemAtPath:path error:nil];

if (attrs != nil) {
    return (NSDate*)[attrs objectForKey: NSFileCreationDate];
} else {
    return nil;
}

This always returns nil. Typing 'po attrs' into the debugger to get the list of key/value pairs in the NSDictionary returns the following..

NSFileGroupOwnerAccountID = 20;
NSFileGroupOwnerAccountName = staff;
NSFileModificationDate = 2010-01-21 11:47:55 +0000;
NSFileOwnerAccountID = 501;
NSFileOwnerAccountName = ben;
NSFilePosixPermissions = 420;
NSFileReferenceCount = 1;
NSFileSize = 338;
NSFileSystemFileNumber = 2234;
NSFileSystemNumber = 42553324;
NSFileType = NSFileTypeRegular;

No creation date.. bah..

Anyone know another way of getting the creation date or does it just not exist in iOS?

Answer 1

This code actually returns the good creation date to me:

NSFileManager* fm = [NSFileManager defaultManager];
NSDictionary* attrs = [fm attributesOfItemAtPath:path error:nil];

if (attrs != nil) {
    NSDate *date = (NSDate*)[attrs objectForKey: NSFileCreationDate];
    NSLog(@"Date Created: %@", [date description]);
} 
else {
    NSLog(@"Not found");
}

Are you creating the file inside the App? Maybe that's where the problem is.