socket.gethostbyaddr( os.environ['REMOTE_ADDR'] error

[Νικόλαος Κούρας]

On 2 Ιαν, 17:47, Roy Smith <r... at panix.com> wrote:
> In article
> <6b787f23-5813-4831-a349-02883f564... at q7g2000yqn.googlegroups.com>,
>  ÉΪÉ«É»όλαος Κούρας <nikos.kou... at gmail.com> wrote:
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> > On 2 ÉßÉΩÉΥ, 16:00, Heiko Wundram <modeln... at modelnine.org> wrote:
> > > Am 02.01.2012 14:25, schrieb ÉΪÉ«É»όλαος Κούρας:
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> > > > On 23 Δεκ 2011, 19:14, Νικόλαος Κούρας<nikos.kou... at gmail.com>  wrote:
> > > >> I dont know why this line host =
> > > >> socket.gethostbyaddr( os.environ['REMOTE_ADDR'] )[0] fails sometimes
> > > >> and some other times works ok retrieving the hostnames correctly.
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> > > > Please i need some help. My webpage doesn't work due to this error...
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> > > The error "herror: (1, ...)" says it all: the DNS-name (i.e., the
> > > <something>.in-addr.arpa name) you're trying to resolve is unknown. Not
> > > all hosts (or rather, IPs) on the internet have reverse lookups: try the
> > > IP 81.14.209.35 from which I'm posting, and dig/nslookup will tell you
> > > that it has no reverse resolution, which would result in gethostbyaddr()
> > > throwing an herror-instance.
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> > I see
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> > > Basically: make the reverse lookup conditional by wrapping it in a
> > > try:/except herror: and assigning an appropriate default for host in
> > > case reverse lookup fails.
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> > Can tou show me how to write this please?
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> try:
>    host =  socket.gethostbyaddr( os.environ['REMOTE_ADDR'] )[0]
> except socket.herror:
>    host = "<unknown host>"

Thank you very much.