「do not backup」 属性をディレクトリにマークするスニペットコード

gistfile1.m

- (void)sampleAddAttributeToFolder
{
  NSFileManager *fileManager = [NSFileManager defaultManager];
  NSString *baseDir = [self paperStandDocumentsBasePath];
  NSError *error;
  BOOL result = [fileManager createDirectoryAtPath:baseDir
                       withIntermediateDirectories:YES
                                        attributes:nil
                                             error:&error];
  
  if (result) {
    NSURL *url = [NSURL fileURLWithPath:baseDir];
    if ([self addSkipBackupAttributeToItemAtURL:url]) {
      NSLog(@"success! could add do not backup attribute to folder");
    }
}

/// <Application_Home>/Library/Private Documents/PapaerStand
#define kPaperStandDocumentsBaseName @"PaperStand"

- (NSString *)paperStandDocumentsBasePath
{
  NSString *libraryPath;
  libraryPath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library"];
  NSString *privateDocumenstPath;
  privateDocumenstPath = [libraryPath stringByAppendingPathComponent:@"Private Documents"];
  NSString *myDocumentsPath;
  myDocumentsPath = [privateDocumenstPath stringByAppendingPathComponent:kPaperStandDocumentsBaseName];
  return myDocumentsPath;
}


- (BOOL)addSkipBackupAttributeToItemAtURL:(NSURL *)URL
{
  if (URL == nil) {
    return NO;
  } else if (![URL isFileURL]){
    return NO;
  }
  
  u_int8_t b = 1;
  int result = setxattr([[URL path] fileSystemRepresentation], "com.apple.MobileBackup", &b, 1, 0, 0);
  if (result == 0) {
    LOG(@"success result:%d path:%@", result, [URL path]);
  } else {
    LOG(@"failur result:%d path:%@", result, [URL path]);
  }
  return result == 0;
}