int ret = sscanf2(data, "%as %d", &name, &age);
int ret = sscanf2(input, "%as %d", &str, &num); if (ret < 0) fprintf(stderr, "sscanf2 error: %s\n", sscanf2_strerror(ret)); // e.g., "Format string error at position 3" sscanf2
return out;