nsswitch.conf - db service for hosts

[Peter Polgar]

Hi,

I am trying to use the db service in nsswitch.conf. I couldn't make it work
so I decided to get some hints from the source code.
A comment in test-netdb.c:310 says that "db is not implemented for hosts".
Also seen in the nss/Makefile:128 that "hosts" is filtered out from the
list of dbs.
Do these mean that db service is not implemented for hosts?
If it is implemented how can I find the path where nsswitch is looking for
the db?

I am on Ubuntu 20.04 LTS with GLIBC 2.31-0ubuntu9.9, libnss-db/focal,now
2.2.3pre1-6build6

Thanks!
Peter