oathtool

OATH one-time password tool. More information: https://www.nongnu.org/oath-toolkit/oathtool.1.html.

oathtool --totp --base32 "secret"

oathtool --totp --now "2004-02-29 16:21:42" --base32 "secret"

oathtool --totp --base32 "secret" "token"