| PASS SP password CRLF
    | PORT check_login SP host_port CRLF
    | EPRT check_login SP STRING CRLF
    | LPRT check_login SP host_lport CRLF
    | PASV check_login CRLF
    | EPSV check_login CRLF
    | EPSV check_login SP STRING CRLF
    | LPSV check_login CRLF
    | TYPE check_login SP type_code CRLF
    | STRU check_login SP struct_code CRLF
    | MODE check_login SP mode_code CRLF
    | ALLO check_login SP NUMBER CRLF
    | ALLO check_login SP NUMBER SP R SP NUMBER CRLF
    | RETR check_login SP pathname CRLF
    | STOR check_login SP pathname CRLF
    | APPE check_login SP pathname CRLF
    | NLST check_login CRLF
    | NLST check_login SP STRING CRLF
    | MLST check_login CRLF
    | MLST check_login SP pathname CRLF
    | MLSD check_login CRLF
    | MLSD check_login SP pathname CRLF
    | LIST check_login CRLF
    | LIST check_login SP pathname CRLF
    | STAT check_login SP pathname CRLF
    | STAT check_login CRLF
    | DELE check_login SP pathname CRLF
    | RNTO check_login SP pathname CRLF
    | ABOR check_login CRLF
    | CWD check_login CRLF
    | CWD check_login SP pathname CRLF
    | HELP check_login CRLF
    | HELP check_login SP STRING CRLF
    | FEAT check_login CRLF
    | NOOP check_login CRLF
    | MKD check_login SP pathname CRLF
    | RMD check_login SP pathname CRLF
    | PWD check_login CRLF
    | CDUP check_login CRLF
    | SITE check_login SP HELP CRLF
    | SITE check_login SP HELP SP STRING CRLF
    | SITE check_login SP UMASK CRLF
    | SITE check_login SP UMASK SP octal_number CRLF
    | SITE check_login SP CHMOD SP octal_number SP pathname CRLF
    | SITE check_login SP IDLE CRLF
    | SITE check_login SP IDLE SP NUMBER CRLF
    | SITE check_login SP GROUP SP username CRLF
    | SITE check_login SP GPASS SP password CRLF
    | SITE check_login SP GPASS CRLF
    | SITE check_login SP NEWER SP STRING CRLF
    | SITE check_login SP NEWER SP STRING SP pathname CRLF
    | SITE check_login SP MINFO SP STRING CRLF
    | SITE check_login SP MINFO SP STRING SP pathname CRLF
    | SITE check_login SP INDEX SP STRING CRLF
    | SITE check_login SP EXEC SP STRING CRLF
    | STOU check_login CRLF
    | STOU check_login SP pathname CRLF
    | SYST check_login CRLF
    | SIZE check_login SP pathname CRLF
    | MDTM check_login SP pathname CRLF
    | OPTS check_login opts CRLF
    | MFF check_login SP CRLF
    | MFCT check_login SP NUMBER SP pathname CRLF
    | MFMT check_login SP NUMBER SP pathname CRLF
    | QUIT CRLF
    | SITE check_login SP ALIAS CRLF
    | SITE check_login SP ALIAS SP STRING CRLF
    | SITE check_login SP GROUPS CRLF
    | SITE check_login SP CDPATH CRLF
    | SITE check_login SP CHECKMETHOD SP method CRLF
    | SITE check_login SP CHECKMETHOD CRLF
    | SITE check_login SP CHECKSUM SP pathname CRLF
    | SITE check_login SP CHECKSUM CRLF
    | SITE check_login SP BUFSIZE CRLF
    | SITE check_login SP BUFSIZEMEASURE SP remote_mtu_size CRLF
    | SITE check_login SP BUFSIZE SP bufsize CRLF
    | PBSZ SP STRING CRLF
    | AUTH SP STRING CRLF
    | PROT SP prot_code CRLF
    | ADAT SP STRING CRLF
    | CCC CRLF
    | REST check_login SP STRING CRLF