On 2009-12-29 14:18:47 -0800, Russ Allbery wrote: > Vincent Lefevre <vinc...@vinc17.org> writes: > > When I compile Mutt or any other portable software (e.g. conforming to > > POSIX), I don't mind if such software isn't integrated with the Debian > > system. I just want it work according to the POSIX spec. If it doesn't > > because the system configuration doesn't comply to POSIX, then the > > system (configuration) is broken. > > I don't think POSIX says what you think it says, but I could be wrong. > Could you cite the exact section that says that systems are required by > POSIX to be configured in the manner that you describe?
I haven't say anything about the configuration, just that POSIX says that a system (locally identified by nodename) has a canonical name. > getaddrinfo does not place such a restriction; AI_CANONNAME is > allowed to fail. Note the use of the word "attempt" Yes, but a failure is something one can expect to happen under some occasions, at least for remote hosts. This doesn't mean that hosts don't have a canonical name, just that this canonical name couldn't be determined. For the local host, I would say that a failure is mostly due to a configuration problem (unless a remote DNS is used, in which case it may be down, and BTW, that's why I think it is a bad idea to use one for something purely local). I'd say that making the request fail on purpose is contrary to POSIX, and I find it not surprising that software could fail to behave correctly because of that. > and the note: > > Since different implementations use different conceptual models, the > terms ``canonical name'' and ``alias'' cannot be precisely defined for > the general case. However, Domain Name System implementations are > expected to interpret them as they are used in RFC 1034. > > I don't believe there's any requirement anywhere in POSIX that the > return value of uname -n be registered in DNS. I haven't said that. And this is often not the case under Debian, i.e. the FQDN is often obtained from /etc/hosts, which has the precedence over DNS (see /etc/nsswitch.conf). > In fact, the POSIX definition of the uname utility specifically > says "the name of this node within an implementation-defined > communications network." Implementation-defined means you cannot > depend on it to be anything in particular without additional > information about the implementation you're using. This is implementation-defined, but still, the host has a canonical name, that should be obtainable with getaddrinfo, as described. BTW, Debian defines /etc/mailname as containing the FQDN. So, this notion is explicitly defined on Debian, and one should expect "hostname -f" to return the same name (according to its documentation). -- Vincent Lefèvre <vinc...@vinc17.net> - Web: <http://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <http://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / Arénaire project (LIP, ENS-Lyon) -- To UNSUBSCRIBE, email to debian-devel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
