Questions about nsd-control zonestatus

Hi!

I would like to feed the zonestatus of our slave-domains into our
monitoring.

# nsd-control zonestatus
zone:   at
        state: ok
        served-serial: "1513598401 since 2017-12-18T12:53:44"
        commit-serial: "1513663202 since 2017-12-19T06:06:09"
zone:   versicherung
        state: ok
        served-serial: "1513605664 since 2017-12-18T14:01:08"
        commit-serial: "1513670464 since 2017-12-19T08:01:10"
...


Are there tools available to parse the output?

Is it possible to get a more structured output (csv, json ...)?

The man page states: The state of the zone is printed as: 'master'
(master zones), 'ok' (slave zone is up-to-date), 'expired' (slave zone
has expired), 'refreshing' (slave zone has transfers active).

Is it possible to detect refresh or axfr errors, e.g. the SOA
refresh-query to the master failed or the SOA query suceeded but the XFR
failed? I would like to detect errors before the status switches to expired.

Thanks
Klaus