The oathtool command line tool can also be used on Linux or Mac systems to provide a one-time password as an alternative to using an authenticator client on a smartphone [Read more ...]

The oathtool command line tool can also be used on Linux or Mac systems to provide a one-time password as an alternative to using an authenticator client on a smartphone

Use as:

oathtool -b --digits=6 --totp=sha1 "ABCDEFGHIJKLMNOPQRSTUVWXYZ012345"