[Nut-upsuser] upsd/upsc, LISTEN and hostname resolution in master/slave

[Charles Lepple]

Somewhat related: has anyone used nss-myhostname to ensure that the
local hostname can be looked up even without DNS? Seems like this is
the intended use case.

Also, assuming NUT has been built against glibc (more than likely, for
most desktop/server Linux distributions), you can use "getent hosts"
to see the effect of the nsswitch.conf settings. This is slightly more
accurate than using a tool like "dig" or "nslookup" because the latter
tools query DNS directly.