The s6-dnsqualify program

s6-dnsqualify qualifies a domain name.

Interface

     s6-dnsqualify domain

s6-dnsqualify qualifies domain according to the "domain" and "search" rules in /etc/resolv.conf. It prints the result on stdout, one FQDN per line.
If the DNSQUALIFY environment variable is set and contains a list of suffixes separated by spaces, tabs, newlines or carriage returns, then this list is used instead of the /etc/resolv.conf rules.