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

Robert Raschke <>
Thu Oct 15 17:48:38 CEST 2009


On Thu, Oct 15, 2009 at 4:28 PM, Raimo Niskanen <
<raimo%>
> wrote:

> On Thu, Oct 15, 2009 at 03:02:40PM +0200, info wrote:
> > Dear Raimo,
> > I can resume: I discovered that gethostbyname call inet_gethost.c
> > I don't understand inet_gethost.c :-(
> > Where "goes" this problem for finding the information ?
> > If we know where and what, we could perhaps find what is missing in my
> windows 2003 ...
> > Hope to read you soon !
> > John
>
> Well, there is not much more to say. inet_gethost.c calls
> struct hostent *gethostbyname(const char *name) in the
> winsock2 library:
>  http://msdn.microsoft.com/en-us/library/ms738524(VS.85).aspx<http://msdn.microsoft.com/en-us/library/ms738524%28VS.85%29.aspx>
> It never returns.
> It is deprecated but that does not mean broken.
> I have a Windows 2003 server that it works on.
> We have not found the reason it differs between
> my server and your server.
> And that is about it.
>
>
>
I can consistently reproduce the hanging gethostbyname() in inet_gethost.exe
on Windows 2003 when I have the 'Microsoft Firewall Client for ISA Server
Version 4.0' installed. This is a specific add-on, nothing to do with
Microsoft Firewall in your Network Properties.

If I remove it, it works fine, if I add it it hangs. Apart from that the
W2003 build is as vanilla as it gets.

Nothing much to go on, but I would not be surprised if some system DLL is
getting in the way. This is very hard to diagnose.

One day I'll get around to compiling inet_gethost.exe in my setup, just to
rule out poor linkage due to the VC++ setup used to build the shipping
executables. If I compile up a trivial gethostbyname() example from MSDN, it
works OK in all circumstances.

There are a few strange dependencies in other shipped Windows files, for
example beam.dll seems to depend on a particular MSVCR80.DLL with the
version 8.0.50727.1433 . And if you have an older Windows machine, you get
the completely unhelpful popup box telling you that your program could not
be run. This has something to do with Windows Side-by-Side DLL deployment,
and I completely fail to grasp what that's all about.

Robby


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