Strange error when moving a folder to temp with moveItemAtPath. Cocoa error 516

Question

I try to move a folder with a file to a temp folder, but I always receive the same error: The operation couldn’t be completed. (Cocoa error 516.)

This is the code, do you see anything strange? Thanks in advance.

    // create new folder
NSString* newPath=[[self getDocumentsDirectory] stringByAppendingPathComponent:@"algo_bueno"];
NSLog(@"newPath %@", newPath);
if ([[NSFileManager defaultManager] fileExistsAtPath:newPath]) {
    NSLog(@"newPath already exists.");
} else {
    NSError *error;
    if ([[NSFileManager defaultManager] createDirectoryAtPath:newPath withIntermediateDirectories:YES attributes:nil error:&error]) {
        NSLog(@"newPath created.");
    } else {
        NSLog(@"Unable to create directory: %@", error.localizedDescription);
        return;
    }
}

// create a file in that folder
NSError *error;
NSString* myString=[NSString stringWithFormat:@"Probando..."];
NSString* filePath=[newPath stringByAppendingPathComponent:@"myfile.txt"];
if ([myString writeToFile:filePath atomically:YES encoding:NSUTF8StringEncoding error:&error]) {
    NSLog(@"File created.");
} else {
    NSLog(@"Failed creating file. %@", error.localizedDescription);
    return;
}

// move this folder and its folder
NSString *tmpDir = NSTemporaryDirectory();
NSLog(@"temporary directory, %@", tmpDir);
if ([[NSFileManager defaultManager] moveItemAtPath:newPath toPath:tmpDir error:&error]) {
    NSLog(@"Movido a temp correctamente");
} else {
    NSLog(@"Failed moving to temp. %@", error.localizedDescription);
}

Solution 1

Error 516 is NSFileWriteFileExistsError

You can't move a file to a place where a file already exists :)

(See docs here - https://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Miscellaneous/Foundation_Constants/Reference/reference.html and search for '516')

---

More usefully, your destination path should be a file name, not a folder. Try this :

// move this folder and its folder
NSString *tmpDir = NSTemporaryDirectory();
NSString *tmpFileName = [tmpDir stringByAppendingPathComponent:@"my-temp-file-name"];
NSLog(@"temporary directory, %@", tmpDir);
if ([[NSFileManager defaultManager] moveItemAtPath:newPath toPath:tmpFileName error:&error]) {
    NSLog(@"Movido a temp correctamente");
} else {
    NSLog(@"Failed moving to temp. %@", error.localizedDescription);
}

Solution 2

Obtain a unique temp folder name by using the following method:

NSFileManager unique file names

CFUUIDRef uuid = CFUUIDCreate(NULL);
CFStringRef uuidString = CFUUIDCreateString(NULL, uuid);
NSString *tmpDir = [[NSTemporaryDirectory() stringByAppendingPathComponent:(NSString *)uuidString];
CFRelease(uuid);
CFRelease(uuidString);
// MOVE IT
[[NSFileManager defaultManager] moveItemAtPath:myDirPath toPath:tmpDir error:&error]

Comments

[Ricardo]

Thanks for reply! I forgot to say I'm working for the iOS platform, although the document and the error code is the same if you change in the URL "mac" by "ios". I tried what you said, removing my app from my simulator and device (so, temp dir is empty) and it says 516. About what you say about a file, in the docs I can read: "moveItemAtPath:toPath:error: Moves the file or directory at the specified path to a new location synchronously" Do you know any other way to move a folder inside tmp folder? A category or library? Thanks!

[Ricardo]

By the way, your code works, but only moves a file, but I prefer to move a folder full of files. Any idea? Perhaps using recursion, but I just wanted to move the folder because deleting the folder (or copy file by file) takes a few seconds (there are many files, about 500 MB). Any idea or suggestion? Thanks a lot for your help.

[deanWombourne]

It should work if you just pass the folder path in instead of a file path i.e. instead of just newPath use [newPath stringByDeletingLastPathComponent] to get the folder that newFile is in?

[Ricardo]

Thanks for reply, but no luck. I receive the same error, 516, an actually I wouldn't like to move the Documents folder to temp, just "a_folder" folder * /Users/ricardo/Library/Application Support/iPhone Simulator/5.0/Applications/A38C0282-D203-44F5-9F4B-AC560F705‌​4D1/Documents/a_fold‌​er * /Users/ricardo/Library/Application Support/iPhone Simulator/5.0/Applications/A38C0282-D203-44F5-9F4B-AC560F705‌​4D1/Documents

[Mat]

this is the best solution if you move folders with same name.