In a file, several line format may be present at the same time, this is not handled with our implementation. See: ``` $ echo -n foo > foo $ ../gnu/src/cksum --algo=sha224 foo > sum $ ../gnu/src/cksum --algo=sha224 --base64 foo >> sum $ cat sum SHA224 (foo) = 0808f64e60d58979fcb676c96ec938270dea42445aeefcd3a4e6f8db SHA224 (foo) = CAj2TmDViXn8tnbJbsk4Jw3qQkRa7vzTpOb42w== $ ../gnu/src/cksum --check sum foo: OK foo: OK $ target/debug/cksum --check sum foo: OK ../target/debug/cksum: WARNING: 1 line is improperly formatted ```