[erlang-questions] is inet:gethostbyname( IP ) correct?

Robert Raschke <>
Wed Oct 14 12:14:46 CEST 2009


This is part of the IP address spec (not sure where to look to find it,
though). I've seen addresses specified like this on and off in various
locations on a wide variety of OSes, for example in a /etc/hosts file you
can write:

localhost  127.1

Robby

On Tue, Oct 13, 2009 at 8:06 PM, caio ariede <> wrote:

> Interesting case.
>
> The result doesn't appear to be an issue, but a feature of the
> gethostbyname
> original implementation, in C code.
>
> You get the same result, testing with PHP:
>
> $ php -r 'var_dump(gethostbyname("12.27"));'
> string(9) "12.0.0.27"
>
> And other interesting results:
>
> $ php -r 'var_dump(gethostbyname("255.2.256"));'
> string(9) "255.2.1.0"
>
> But I can't see where it's really useful.
>
> Caio Ariede
> http://caioariede.com/
>
>
> On Tue, Oct 13, 2009 at 3:15 PM, Garry Hodgson <
> >wrote:
>
> > recently, a bug in my code caused us to pass a string
> > representing a floating point number to inet:gethostbyname().
> > i would have expected it to return an error, but instead it
> > returned an ip address, but one that made no sense to me:
> >
> > 1> inet:gethostbyname( '12.27' ).
> > {ok,{hostent,"12.27",[],inet,4,[{12,0,0,27}]}}
> >
> > so my question is, is this behavior correct, and if so, what
> > exactly does it mean that a lookup of '12.27' maps to '12.0.0.27'?
> >
> > thanks
> >
> > --
> > Garry Hodgson
> > Lead Member of Technical Staff
> > AT&T Chief Security Office (CSO)
> >
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