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Re: using libcurl with persistent connections

From: Dan Fandrich <>
Date: Wed, 10 Sep 2014 23:24:58 +0200

On Tue, Sep 09, 2014 at 09:31:16PM -0400, Keith Broerman wrote:
> I'm trying to use libcurl to build a HTTP client that subscribes one time to an
> event service and waits to receive events on a persistent connection.  I'm
> starting from the sendrecv.c example code.  My libcurl-based client subscribes
> to an event by sending a Http Get to my server-side eventing code (a FastCGI
> process.)  I receive the first event back OK.  But after that point the select
> () call in wait_on_socket() always indicates that data is available to be read,
> when in fact curl_easy_recv() says there's no data to be read.  It's easy to
> see this by commenting out the break statement in the sendrecv.c code below.

This sounds like it's using a normal HTTP transfer, albeit a slow one, in which
case curl_easy_recv() is the wrong API to use. It should be using
curl_easy_perform(), or if you're using the multi API, one of the multi perform
commands instead. Very, very few programs need curl_easy_recv() and

> Any suggestions on what is needed so that the select(readFDs) gets cleared
> after curl_easy_recv() says that all data has been read/processed?

>>> Dan
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Received on 2014-09-10