Expect Header Issue for .NET developers - Twitter Development Talk

Message from discussion Expect Header Issue for .NET developers

Tom Morris

More options Dec 24 2008, 2:57 pm

From: Tom Morris <t...@tommorris.org>

Date: Wed, 24 Dec 2008 11:57:49 -0800 (PST)

Local: Wed, Dec 24 2008 2:57 pm

Subject: Re: Expect Header Issue for .NET developers

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On Dec 24, 4:31 am, JakeS <jakesteven...@gmail.com> wrote:

> Looks like twitter is updating something and their servers are
> returning error 417 for a lot of requests. I looked into it and found
> that .NET automatically includes an Expect header containing "100-
> continue" on every request unless you specifically tell it not to.

> So for any .NET devs having trouble, you can set
> System.Net.ServicePointManager.Expect100Continue = false before making
> your request to get past this issue.

A lot of libraries follow this behaviour. A Twitter app I wrote in PHP
a while back has been logging 417s most of today. I logged in and
added:
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Expect:'));

Other libcurl-based libraries may be affected. There are plenty of
reports about 417 and Expect on the cURL website - http://curl.haxx.se/
- and on the websites of particular language bindings.

--
Tom Morris (@tommorris)
<http://tommorris.org>

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