NSFileManager createSymbolicLinkAtURL example ios

createSymbolicLinkAtURL :withDestinationURL:error:

Creates a symbolic link at the specified URL that points to an item at the given URL.

- (BOOL)createSymbolicLinkAtURL:(NSURL *)url withDestinationURL:(NSURL *)destURL error:(NSError **)error

Parameters

url

The file URL at which to create the new symbolic link. The last path component of the URL issued as the name of the link.

destURL

The file URL that contains the item to be pointed to by the link. In other words, this is the destination of the link.

error

On input, a pointer to an error object. If an error occurs, this pointer is set to an actual error object containing the error information. You may specify nil for this parameter if you do not want the error information.

Return Value of [NSFileManager createSymbolicLinkAtURL]

YES if the symbolic link was created or NO if an error occurred. This method also returns NO if a file, directory, or link already exists at path.

Discussion

This method does not traverse symbolic links contained in destPath, making it possible to create symbolic links to locations that do not yet exist. Also, if the final path component in path is a symbolic link, that link is not followed.

Example of [NSFileManager createSymbolicLinkAtURL]

- (void)createSymbolicLinksForURL:(NSURL *)url inDirectory:(NSURL *)directory {

    NSFileManager *fileManager = [NSFileManager defaultManager];

    NSDirectoryEnumerator *dirEnum = [fileManager enumeratorAtURL:url
                                       includingPropertiesForKeys:[NSArray arrayWithObject:NSURLIsDirectoryKey] 
                                                          options:NSDirectoryEnumerationSkipsHiddenFiles | NSDirectoryEnumerationSkipsPackageDescendants
                                                     errorHandler:nil];

    NSArray *resourceKeys = [NSArray arrayWithObjects:NSURLIsSymbolicLinkKey, NSURLIsDirectoryKey, nil];

    for (NSURL *bundledURL in dirEnum) {

        if ([[[bundledURL resourceValuesForKeys:resourceKeys error:nil] objectForKey:NSURLIsDirectoryKey] boolValue]) continue;

        NSArray *bundledURLPathComponents = [bundledURL pathComponents];

        NSURL *destinationURL = directory;

        for (NSUInteger componentIndex = [bundledURLPathComponents count] - dirEnum.level; componentIndex < [bundledURLPathComponents count]; componentIndex++) {

            destinationURL = [destinationURL URLByAppendingPathComponent:[bundledURLPathComponents objectAtIndex:componentIndex]];
        }

        if ([fileManager fileExistsAtPath:destinationURL.path]) {

            if ([[[destinationURL resourceValuesForKeys:resourceKeys error:nil] objectForKey:NSURLIsSymbolicLinkKey] boolValue]) {

                [fileManager removeItemAtURL:destinationURL error:nil];
            }
            else {

                continue;
            }
        }

        NSURL *container = [destinationURL URLByDeletingLastPathComponent];
        if (![fileManager fileExistsAtPath:container.path]) [fileManager createDirectoryAtURL:container withIntermediateDirectories:YES attributes:nil error:nil];

        NSError *error = nil;
        [fileManager createSymbolicLinkAtURL:destinationURL withDestinationURL:bundledURL error:&error];
        if (error) NSLog(@"Failed to create symbolic link for %@ (Error: %@)", bundledURL, error);
    }
}