Does anyone know how to close an FTP session with RCurl?? I am trying to
automate the process of downloading snow data from a government website, and
their server is throttling the connection after a few files are downloaded.? I
contacted their system administrator, who wrote: ?My suspicion at this point is
that the getURL commands are opened and perform the function asked, then linger
in wait for 15 minutes until or ftp server closes the idle sessions. Is there a
way to tell R to close the sessions??
I?ve perused the RCurl manual but I don?t see a way to close sessions.? I tried
copying the following example from the RCurl manual, but it didn?t solve the
problem.? I?m a novice at this and I don?t understand the relationship between
handles and sessions, so I am probably missing something.
#EXAMPLE from getCurl(), p. 39
if(url.exists("http://www.omegahat.net/RCurl/index.html")) {
??curl = getCurlHandle()
?? getURL("http://www.omegahat.net/RCurl/index.html", curl = curl)
?? #getCurlInfo(curl) # I skipped this step
?? rm(curl) # release the curl! (does this end the session???)
}
Thanks!
John
[[alternative HTML version deleted]]
No expert here, and this isn't tested. It seems you can set the
forbid.reuse option which will cause curl to shutdown the connection
after transfer is complete.
if(url.exists("http://www.omegahat.net/RCurl/index.html")) {
curl <- getCurlHandle()
curlSetOpt(.opts=list(forbid.reuse=1),curl=curl)
getURL("http://www.omegahat.net/RCurl/index.html", curl = curl)
}
On Tue, Jun 14, 2016 at 2:41 PM, J Payne <jcpayne at uw.edu>
wrote:> Does anyone know how to close an FTP session with RCurl? I am trying to
automate the process of downloading snow data from a government website, and
their server is throttling the connection after a few files are downloaded. I
contacted their system administrator, who wrote: ?My suspicion at this point is
that the getURL commands are opened and perform the function asked, then linger
in wait for 15 minutes until or ftp server closes the idle sessions. Is there a
way to tell R to close the sessions??
>
>
>
> I?ve perused the RCurl manual but I don?t see a way to close sessions. I
tried copying the following example from the RCurl manual, but it didn?t solve
the problem. I?m a novice at this and I don?t understand the relationship
between handles and sessions, so I am probably missing something.
>
>
>
> #EXAMPLE from getCurl(), p. 39
>
> if(url.exists("http://www.omegahat.net/RCurl/index.html")) {
>
> curl = getCurlHandle()
>
> getURL("http://www.omegahat.net/RCurl/index.html", curl =
curl)
>
> #getCurlInfo(curl) # I skipped this step
>
> rm(curl) # release the curl! (does this end the session???)
>
> }
>
>
>
> Thanks!
>
>
>
> John
>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
Thanks Tom! I tried that and it didn?t work, but perhaps there are other problems. The system administrator wrote ?I think closing sessions immediately upon completion of the transfer, or continuing to use the same session for additional requests would both have a similar and positive effect.? However, I?ve now tried your solution to close the session, and also tried using one curl handle throughout, but the throttling persists. John On 6/14/16, 1:00 PM, "Tom Wright" <tom at maladmin.com> wrote:>No expert here, and this isn't tested. It seems you can set the >forbid.reuse option which will cause curl to shutdown the connection >after transfer is complete. > >if(url.exists("http://www.omegahat.net/RCurl/index.html")) { > curl <- getCurlHandle() > curlSetOpt(.opts=list(forbid.reuse=1),curl=curl) > getURL("http://www.omegahat.net/RCurl/index.html", curl = curl) >} > >On Tue, Jun 14, 2016 at 2:41 PM, J Payne <jcpayne at uw.edu> wrote: >> Does anyone know how to close an FTP session with RCurl? I am trying to automate the process of downloading snow data from a government website, and their server is throttling the connection after a few files are downloaded. I contacted their system administrator, who wrote: ?My suspicion at this point is that the getURL commands are opened and perform the function asked, then linger in wait for 15 minutes until or ftp server closes the idle sessions. Is there a way to tell R to close the sessions?? >> >> >> >> I?ve perused the RCurl manual but I don?t see a way to close sessions. I tried copying the following example from the RCurl manual, but it didn?t solve the problem. I?m a novice at this and I don?t understand the relationship between handles and sessions, so I am probably missing something. >> >> >> >> #EXAMPLE from getCurl(), p. 39 >> >> if(url.exists("http://www.omegahat.net/RCurl/index.html")) { >> >> curl = getCurlHandle() >> >> getURL("http://www.omegahat.net/RCurl/index.html", curl = curl) >> >> #getCurlInfo(curl) # I skipped this step >> >> rm(curl) # release the curl! (does this end the session???) >> >> } >> >> >> >> Thanks! >> >> >> >> John >> >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code.