FileFilter::New(descriptor_file->get_fd(), signature_filter.c_str()));
if (descriptor_filter == NULL) {
fprintf(stderr, "Unable to open descriptor output file: %m\n");
FileFilter::New(descriptor_file->get_fd(), signature_filter.c_str()));
if (descriptor_filter == NULL) {
fprintf(stderr, "Unable to open descriptor output file: %m\n");