systemd: how to list enabled services

[Bill Nottingham]

Toshio Kuratomi (a.badger at gmail.com) said: 
> on and off map to systemctl enable whereas chkconfig would set the service
> on and off in certain runlevels.  So they're now more similar to chkconfig
> --add.

Not exactly. chkconfig --add doesn't change the state of the service, unless
it hasn't been set up at all.

> The <no command> case doesn't check targets like chkconfig does with
> runlevels.

If you pass --levels to chkconfig, it doesn't forward to systemd.

Bill