The check-hostname script is a migration aid for sendmail(1M). This script tries to determine the local host's fully-qualified host name (FQHN) in a manner similar to sendmail(1M). If check-hostname is able to determine the FQHN of the local host, it reports success. Otherwise, check-hostname reports how to reconfigure the system so that the FQHN can be properly determined.

/etc/hosts

host name database

/etc/nsswitch.conf

name service switch configuration file

/etc/resolv.conf

configuration file for name server routines

See attributes(5) for descriptions of the following attributes:

sendmail(1M), hosts(4), attributes(5)