Issue with Returning a Directory Enumerator from Nsfilemanager Using Enumeratoraturl in Swift

Issue with returning a Directory Enumerator from NSFileManager using enumeratorAtUrl in Swift

Try this:

let enumerator:NSDirectoryEnumerator = manager.enumeratorAtURL(url, includingPropertiesForKeys: keys, options: NSDirectoryEnumerationOptions(), errorHandler: nil)

Or in short, pass in NSDirectoryEnumerationOptions() instead of "0".

"0" is not really a member of the enumeration it is looking for.

NSFileManager:enumeratorAtURL: returns a different form of URL to NSFileManager:URLForDirectory

I had to switch to doing this instead:

NSDirectoryEnumerator *dirEnum = [self.fileManager enumeratorAtPath: [NSHomeDirectory() stringByAppendingPathComponent:@"/Library/Application Support/"]];

FileManager.default.enumerator does not return any files

FileManager has two methods to obtain a directory enumerator:

• enumerator(atPath path: String)
• enumerator(at url: URL, ...)

The first one returns an enumerator which enumerates strings
(the file paths), the second one returns an enumerator which
enumerates URLs.

Your code uses the URL-based enumerator, therefore the conditional
casts to as? String fail and no output is produced.

You have to cast to URL instead:

if let dirContents = FileManager.default.enumerator(at: documentsUrl.resolvingSymlinksInPath(), includingPropertiesForKeys: nil) {

    while let url = dirContents.nextObject() as? URL {
        print(url.path)
    }
}

You can also iterate with a for-loop:

if let dirContents = FileManager.default.enumerator(at: documentsUrl.resolvingSymlinksInPath(), includingPropertiesForKeys: nil) {

    for case let url as URL in dirContents {
        print(url.path)
    }
}

Enumerating over a directory gives me an error when I try to follow aliases

I‘m pretty damn sure the answer is right there in the error message:

The file “Musik” couldn’t be opened because you don’t have permission to view it.

Reveal the destination of the alias in the Finder application and check its permission via “Get Info” or ls -l@ in the Terminal — I’d bet that your user account david is not being granted one of the following permissions:

• read
• execute
• list

The last one will typically not be visible on the command line except in combination with an explicit deny-access-control-entry.

How do I enumerate through a directory in Objective-C, and essentially clear out all the directories of non-directory files?

Something like this will work:

NSURL *rootURL = ... // File URL of the root directory you need
NSFileManager *fm = [NSFileManager defaultManager];
NSDirectoryEnumerator *dirEnumerator = [fm enumeratorAtURL:rootURL
                    includingPropertiesForKeys:@[NSURLNameKey, NSURLIsDirectoryKey]
                    options:NSDirectoryEnumerationSkipsHiddenFiles
                    errorHandler:nil];

for (NSURL *url in dirEnumerator) {
    NSNumber *isDirectory;
    [url getResourceValue:&isDirectory forKey:NSURLIsDirectoryKey error:NULL];
    if (![isDirectory boolValue]) {
        // This is a file - remove it
        [fm removeItemAtURL:url error:NULL];
    }
}

Why is NSDirectoryEnumerator picking up hidden files here?

Actually, the real problem is that you're using the wrong operator to specify the mask:

NSDirectoryEnumerationSkipsPackageDescendants ||  NSDirectoryEnumerationSkipsHiddenFiles

does Boolean OR, giving you 1, which isn't a useful options mask. You need to use the single pipe:

NSDirectoryEnumerationSkipsPackageDescendants |  NSDirectoryEnumerationSkipsHiddenFiles

which is bitwise OR.

OLD ANSWER:

You need to actually request the properties that you're going to look at:

dirEnumerator = [fileManager enumeratorAtURL:item 
                  includingPropertiesForKeys:[NSArray arrayWithObject:NSURLIsHiddenKey]
                                     options:NSDirectoryEnumerationSkipsPackageDescendants || NSDirectoryEnumerationSkipsHiddenFiles 
                                errorHandler:nil];

from the -[NSURL getResourceValue:forKey:error:] doc:

Discussion
value is set to nil if the requested resource value is not defined for the URL. In this case, the method still returns YES.

NSFileManager delete contents of directory

E.g. by using a directory enumerator:

NSFileManager *fileManager = [[NSFileManager alloc] init];
NSDirectoryEnumerator *enumerator = [fileManager enumeratorAtPath:path];    
NSString *file;

while (file = [enumerator nextObject]) {
    NSError *error = nil;
    BOOL result = [fileManager removeItemAtPath:[path stringByAppendingPathComponent:file] error:&error];

    if (!result && error) {
        NSLog(@"Error: %@", error);
    }
}

Swift

let fileManager = NSFileManager.defaultManager()
let enumerator = fileManager.enumeratorAtURL(cacheURL, includingPropertiesForKeys: nil, options: nil, errorHandler: nil)

while let file = enumerator?.nextObject() as? String {
    fileManager.removeItemAtURL(cacheURL.URLByAppendingPathComponent(file), error: nil)
}

File count of a directory in Objective-C

Straight from the docs:

If you need to recurse into subdirectories, use
enumeratorAtURL:includingPropertiesForKeys:options:errorHandler: as
shown in “Using a Directory Enumerator”).

Check also here:
Using a Directory Enumerator

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