Usage: oathtool [OPTION]... [KEY [OTP]]...
Generate and validate OATH one-time passwords.  KEY and OTP is the string '-'
to read from standard input, '@FILE' to read from indicated filename, or a hex
encoded value (not recommended on multi-user systems).

  -h, --help                    Print help and exit
  -V, --version                 Print version and exit
      --hotp                    use event-based HOTP mode  (default=on)
      --totp[=MODE]             use time-variant TOTP mode (values "SHA1",
                                  "SHA256", or "SHA512")  (default=`SHA1')
  -b, --base32                  use base32 encoding of KEY instead of hex
                                  (default=off)
  -c, --counter=COUNTER         HOTP counter value
  -s, --time-step-size=DURATION TOTP time-step duration  (default=`30s')
  -S, --start-time=TIME         when to start counting time steps for TOTP
                                  (default=`1970-01-01 00:00:00 UTC')
  -N, --now=TIME                use this time as current time for TOTP
                                  (default=`now')
  -d, --digits=DIGITS           number of digits in one-time password
  -w, --window=WIDTH            number of additional OTPs to generate or
                                  validate against
  -v, --verbose                 explain what is being done  (default=off)

Report bugs to: oath-toolkit-help@nongnu.org
oathtool home page: <https://www.nongnu.org/oath-toolkit/>
General help using GNU software: <https://www.gnu.org/gethelp/>