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Re: CoAP support in libcurl for the Internet of Things

From: Daniel Stenberg <>
Date: Thu, 17 May 2018 10:54:03 +0200 (CEST)

On Tue, 8 May 2018, Olaf Bergmann wrote:

>> If I would be negative about something, then it is that libcoap is
>> seriously badly documented
> Since libcoap has evolved from a low-level implementation for embedded
> developers who really know (and want to know) their code into a package for
> major Linux distributions such as Debian, Ubuntu, Arch, the API as well as
> the documentation have been improved a lot.

Really? I googled "libcoap API". Found

I clicked "version 4.1.2" which is the latest I see there and landed on

That's virtually a blank page. doxygen generated. I've never seen a library
with good API docs generated from doxygen.

Ok, go back and click "user guide" instead? That page says "Unfortunately, the
user guide is not yet ready. There is much to do…"

This makes it tricky for a casual observer such as myself to figure out and
learn how the API works so that I can get an image how hard it would be to
incorporate into something like libcurl.

> The current development branch that is intended to become the next major
> release soon already has a good amount of manual pages that document the
> API. The web site re-factoring and user guide writing are in progress.

So this new good documentation is not available online yet?

>> It is also yet another dependency that relies on its own TLS library, which
>> seems to mostly be OpenSSL on posix systems.
> libcoap comes with an interface to enable intergration of different TLS
> libraries. For now, these are OpenSSL and tinyDTLS, but GnuTLS
> integration is in development as well.

Cool, but may still offer a challenge for the libcurl build setup.

> Finally, it might be worthwhile pointing out that libcoap currently runs on
> Linux, MacOS, and Windows and has an actively contributing community.


Do you run it through coverity or another static analyzer frequently?

I think you should consider -Werror on your travis builds and fix those build
warnings you have.

I would encourage you to do what it takes to get a badge here:


Received on 2018-05-17