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Re: «--etag-compare» while «--continue-at»

From: Jeremy Nicoll via curl-users <>
Date: Sat, 09 May 2020 11:55:52 +0100

On Sat, 9 May 2020, at 11:09, Коваленко Анатолий Викторович via curl-users wrote:
> You asked an example. My script saved (as JSON) history of
> HTTP-headers while downloading with
> breaks of provider's connection.
> Page:
> File:
> Call: curl.exe -C - -D Dump.txt -O -R -y 10 -Y 1024 $HRef
> You can see, that changed and restored for a short time (from
> «05:12:42» to «08:19:29») values of
> next parameters:
> «ETag» (from «5ea97a29-38b5528» to «5ea97a2a-38b5528» and back);
> «Last-Modified» (from «Wed, 29 Apr 2020 12:59:21 GMT» to «Wed, 29 Apr
> 2020 12:59:22 GMT» and back);

If the file being grabbed has changed while you've been trying to grab it,
would this not make sense?

Or, possibly the place you're grabbing it from keeps the file on several
servers and the file timestamps are not all the same. Maybe some of your
attempts were being serviced by one server and another attempt by a
different server?

(I'm only guessing. I have no idea if cURL is supposed to be able to tell
if this were to happen. I can't see how cURL would know though if the
server(s) at the far end don't say.)

Jeremy Nicoll - my opinions are my own.
Received on 2020-05-09