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Re: FTP response timeout

From: Dan Fandrich <>
Date: Thu, 28 Jun 2012 22:31:51 +0200

On Thu, Jun 28, 2012 at 09:33:44AM -0700, Jeff McKay wrote:
> How would I find out if CURLOPT_TCP_KEEPALIVE is supported on my
> platform (Windows)?

If you enable logging, you should see a message "Failed to set
SO_KEEPALIVE on fd X" if setting keepalive failed on a recent

> So, there would be no solution if I am using a libcurl version prior
> to 7.25? I am trying to avoid

--keepalive-time was added to the curl front-end in 7.18.0, but much
later to libcurl. Your application can always enable TCP keepalive
callback function even in older libcurl versions.

> the pain of doing an upgrade. Another bit of advice I got was to
> periodically send a NOOP
> instruction to the ftp server on the control channel, but I don't
> think I have this capability
> if libcurl is handling the ftp transfer, correct?

Correct. Adding NOOP support on the ftp control channel has been
suggested in the past, but nobody has stepped up and submitted any
code that implements it.

>>> Dan
List admin:
Received on 2012-06-28