Nico Kadel-Garcia wrote: > Tim Rice wrote: > > Bob Proulx wrote: > > > Getting a FQDN is truly not trivial. :-( > > > > True, and some hostname (ubuntu, centos, etc) implimentations have > > "hostname -f" for the FQDN. That is a dangerous test that if run as root on say HP-UX definitely (ask me how I know) will set the hostname to "-f"[1] if it has the permission to do so instead of querying the hostname. The traditional hostname command took no options and when presented with an argument would set the hostname to that argument. [1] https://www.freebsd.org/cgi/man.cgi?query=hostname&manpath=HP-UX+11.22 Additionally hostname -f (--fqdn) performs a DNS look up of the IP address and returns "a" DNS name found. This is problematic itself in a number of ways. One being if the host has multiple IP addresses which individually have different associated names. It's a terrible non-solution IMNHO. > It's especially aggravated by many configuration tools listing the > short hostname first, then the full hostname, in /etc/hosts. i.e.: > > 127.0.0.1 short.long.com short localhost.localdomian localhost I know what you meant to say. But your example showed the reversed statement in the normal situation with the long name first and the short name afterward. And the above combination is problematic in ways that are off-topic to the original problem here. The /etc/hosts format is usually documented like this: IP_address canonical_hostname [aliases...] The first name after the IP address should be the FQDN and is the one returned when doing a lookup on the IP address. Short names and aliases appear afterward in the entry line. In this case, coupled with 127.0.0.1, this creates a problem because 127.0.0.1 should map back to localhost. But adding the long hostname on that entry causes 127.0.0.1 to map to the long hostname instead of locahost. However this discussion would be long and off-topic from the original issue. Bob _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
