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Re: Enabled multiple SSL backends

From: Daniel Stenberg <>
Date: Wed, 30 Aug 2017 09:58:32 +0200 (CEST)

On Mon, 28 Aug 2017, Rich Gray wrote:

> I am curious about the manpage statement "This function can only be called
> once". Shouldn't this be something more like "This function can only be
> used to select an SSL library once."

Correct. I'll edit that paragraph.

> Is the avail list a list of all possible libcurl backends or a list of
> backends supported by the current library or a the valid libraries on the
> current system?

It returns the list that this specific build supports. In a future that might
return SSL backends we don't even know the name of today.

> I suspect the first case, given there appear to be CURLSSLBACKEND_* defines
> for each library. This is also the only sane way the ID#s in the example
> could be stable? They don't change, do they?

Right, they are fixed and will never change.

> "If the specified SSL backend is not available, the function returns
> CURLSSLSET_UNKNOWN_BACKEND and sets the "avail" pointer to a NULL-terminated
> list of available SSL backends." Would it be correct to follow this with
> "In this case, you may call the function again to try to select a different
> backend."??


I've edited the man page now to clarify all these points. Thanks!

Received on 2017-08-30