[R] problems with download.file() from ftp?

[zack holden]

Professor Ripley and Brian Rowe,
Thank you both for your helpful suggestions. I was unable to solve this problem. Apparently there is a passive FTP server that is not supported by R. I'll have to find another programming language, perhaps IDL, that can do this. Manually retrieving the hundreds of files I need is not an option. 
 
thank you again for your attempts to help me. 
 
Best regards,
Zack


> Date: Mon, 12 Jan 2009 16:37:43 +0000
> From: ripley at stats.ox.ac.uk
> To: zack_holden at hotmail.com
> CC: r-help at r-project.org
> Subject: Re: [R] problems with download.file() from ftp?
> 
> First, try the example in the test file (tests/internet.R)
> 
> read.table("ftp://ftp.stats.ox.ac.uk/pub/datasets/csb/ch11b.dat")
> 
> or
> 
> download.file("ftp://ftp.stats.ox.ac.uk/pub/datasets/csb/ch11b.dat", 
> "test"
> 
> That is known to work on many, many R systems.
> 
> I get the same error as you on that URL, but it looks to me that the 
> site required PASV ftp, something R's download.file does not support. 
> From the detailed logs (options(internet.info=0)
> 
> <<<
> 230---------------------------------------------------------
> 230- Welcome To The
> 230- Natural Resources Conservation Service - USDA
> 230- NATIONAL WATER and CLIMATE CENTER
> 230---------------------------------------------------------
> 230-
> 230- The Local Date and Time is Mon Jan 12 08:30:25 2009
> 230- Current Directory is /
> 230- Information Contact is: info at wcc.nrcs.usda.gov
> 230- -----------------------------------------------------------
> 230- Note that data files herein are at most updated once an hour.
> 230-
> 230 Guest login ok, access restrictions apply.
> 
> --
> 19: In download.file(url, dest) :
> ---
> 
> --
> 20: In download.file(url, dest) : Got 230
> 21: In download.file(url, dest) : Invalid answer to PASV
> 
> Since you are on Windows, using --internet2 (see the rw-FAQ) might 
> work.
> 
> On Mon, 12 Jan 2009, zack holden wrote:
> 
>>
>> Dear list,
>>
>> I am trying to download a text file from an ftp site using download.file().
>>
>> I used the following code:
>> url <- "ftp://ftp.wcc.nrcs.usda.gov/data/snow/snow_course/table/history/idaho/13e19.txt"
>> dest <- "c:/test/downloadtest.txt"
>> download.file(url, dest)
>> I get this error message, indicating that R is unable to open the connection:
>> trying URL 'ftp://ftp.wcc.nrcs.usda.gov/data/snow/snow_course/table/history/idaho/13e19.txt'
>> Error in download.file(url, dest) :
>> cannot open URL 'ftp://ftp.wcc.nrcs.usda.gov/data/snow/snow_course/table/history/idaho/13e19.txt'
>>
>> I'm sure there is a simple solution that allows R to open this connection, but after reading the "url" help file for an hour, I can't seem to find the solution. Is anyone willing to help me solve this problem?
>>
>> thanks in advance for any advice,
>>
>> Zack
> 
> -- 
> Brian D. Ripley, ripley at stats.ox.ac.uk
> Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
> University of Oxford, Tel: +44 1865 272861 (self)
> 1 South Parks Road, +44 1865 272866 (PA)
> Oxford OX1 3TG, UK Fax: +44 1865 272595