Re: [R-pkg-devel] download.file and https

[Paul Gilbert]

On 07/02/2015 11:52 PM, Duncan Murdoch wrote:
On 03/07/2015 5:24 AM, Paul Gilbert wrote:


On 07/02/2015 10:52 PM, Henrik Bengtsson wrote:
  From R 3.2.0, check:

capabilities("libcurl")
libcurl
     TRUE

TRUE means R was built such that HTTPS is supported.  If you see
FALSE, make sure libcurl is available when/if you build R from source.

I do have TRUE for this. The default behaviour still does not work.

Have you tried specifying the protocol explicitly, i.e.

  download.file("https://research.stlouisfed.org/fred2/series/M2/downloaddata/M2.csv";, 
destfile = tmp, method="libcurl")

?

Yes. The default does not accept a string with https.  It gives 
"unsupported URL scheme".

A few people have mentioned workarounds or setting options. But, as 
Joshua mentioned, the question is really about best practice to make a 
package robust on all platforms, and tests that pass on CRAN.

Paul


Duncan Murdoch


Paul


/Henrik

On Thu, Jul 2, 2015 at 7:46 PM, Paul Gilbert <pgilbert...@gmail.com> wrote:
(This problem with download.file() affects quantmod, and possibly several
other packages. e.g. getSymbols('M2',src='FRED') fails.)

I think the St Louis Fed has moved to using https for connections, and I
believe all the US government web sites are doing this. An http request is
automatically switched to https. The default download.file method does not
seem to handle this, but method="wget" does:

   tmp <- tempfile()

download.file("http://research.stlouisfed.org/fred2/series/M2/downloaddata/M2.csv";,
destfile = tmp)
trying URL
'http://research.stlouisfed.org/fred2/series/M2/downloaddata/M2.csv'
Error in
download.file("http://research.stlouisfed.org/fred2/series/M2/downloaddata/M2.csv";,
:
    cannot open URL
'http://research.stlouisfed.org/fred2/series/M2/downloaddata/M2.csv'



download.file("http://research.stlouisfed.org/fred2/series/M2/downloaddata/M2.csv";,
destfile = tmp, method="wget")
--2015-07-02 22:29:49--
http://research.stlouisfed.org/fred2/series/M2/downloaddata/M2.csv
Resolving research.stlouisfed.org (research.stlouisfed.org)... 65.89.18.120
Connecting to research.stlouisfed.org
(research.stlouisfed.org)|65.89.18.120|:80... connected.
HTTP request sent, awaiting response... 301 Moved Permanently
Location:
https://research.stlouisfed.org/fred2/series/M2/downloaddata/M2.csv
[following]
--2015-07-02 22:29:49--
https://research.stlouisfed.org/fred2/series/M2/downloaddata/M2.csv
Connecting to research.stlouisfed.org
(research.stlouisfed.org)|65.89.18.120|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [text/x-comma-separated-values]
Saving to: ‘/tmp/RtmpOX7kA1/file1ba639d7fd0f’

      [ <=>                                   ] 34,519       178KB/s   in 0.2s

2015-07-02 22:29:50 (178 KB/s) - ‘/tmp/RtmpOX7kA1/file1ba639d7fd0f’ saved
[34519]

Paul

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