CFISizeOfFilesAtPaths.mm

uint64_t CFISizeOfFilesAtPaths(NSArray *inArray) {
  uint64_t accumulator = 0;
	NSString *fileString = nil;
	for (id file in inArray) {
		if ([file isKindOfClass:NSString.class]) {
			fileString = file;
		} else if ([file isKindOfClass:NSURL.class]) {
			fileString = [file path];
		}
		NSDictionary *fileAttributes = [NSFileManager.defaultManager attributesOfItemAtPath:fileString error:nil];
		BOOL fileIsDirectory = [fileAttributes.fileType isEqualToString:NSFileTypeDirectory];
		BOOL fileIsSymbolicLink = [fileAttributes.fileType isEqualToString:NSFileTypeSymbolicLink];
		if (fileIsDirectory) {
			NSMutableArray *allFiles = @[].mutableCopy;
			for (NSString *directoryFile in [NSFileManager.defaultManager contentsOfDirectoryAtPath:fileString error:nil]) {
				[allFiles addObject:[fileString stringByAppendingPathComponent:directoryFile]];
			}
			accumulator += CFISizeOfFilesAtPaths(allFiles);
		} else if (fileIsSymbolicLink) {
			NSString *traversedPath = [NSFileManager.defaultManager destinationOfSymbolicLinkAtPath:fileString error:nil];
			NSDictionary *traversedFileAttributes = [NSFileManager.defaultManager attributesOfItemAtPath:traversedPath error:nil];
			accumulator += traversedFileAttributes.fileSize;
		} else {
			accumulator += fileAttributes.fileSize;
		}
	}
	return accumulator;
}