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Re: Why does multi_curl_perform return CURLE_UNSUPPORTED_PROTOCOL

From: Dan Fandrich <>
Date: Mon, 7 Mar 2011 14:40:24 -0800

On Mon, Mar 07, 2011 at 05:23:44PM -0500, Saqib Ali wrote:
> I have been successfully using the easy interface now for several days (using
> SFTP to do uploads). I'm now learning the multi-interface. I'm having an odd
> problem.
> I have created 3 easy interfaces (that I know have worked in the past) and I'm
> stacking them onto a multi-interface using curl_multi_add_handle(). When I then
> run curl_multi_perform(), I'm surprised to find that it doesn't work. In fact
> the return value of curl_multi_perform is CURLE_UNSUPPORTED_PROTOCOL. That's
> very strange. After the curl_multi_perform fails, I try just running

It's especially strange since CURLE_UNSUPPORTED_PROTOCOL isn't an error that
can be returned by curl_multi_perform(). The enumerated set of errors that
are returned are the CURLMcode errors, NOT the CURLcode errors.

I suggest starting with an example program in docs/examples/ to see how the
multi parts all hang together.

>>> Dan
List admin:
Received on 2011-03-07