Read reads structured binary data from r into data. Data must be a pointer to a fixed-size value or a slice of fixed-size values. Bytes read from r are decoded using the specified byte order and written to successive fields of the data. When reading into structs, the field data for fields with blank (_) field names is skipped; i.e., blank field names may be used for padding. When reading into a struct, all non-blank fields must be exported.