[R] installing package help with limited permissions

[Duncan Murdoch]

On 10/30/2006 11:25 AM, Eva Goldwater wrote:
> Hello,
> 
> I administer a student (Windows based) computer lab, which has R 
> installed.  I want to permit students to install R packages, but of 
> course they don't have write permission to R root folder.  Following FAQ 
> suggestion, I've set up a folder that they can write to, and set the 
> R_LIB parameter on the shortcut to this folder.  So  far, so good - they 
> can now install packages. However, I have not found any way to get the 
> corresponding help files installed. 
> 
> FAQ says the help files require write permission to R installation 
> folder.  This seems pretty extreme.  Is there some subfolder that would 
> do the trick?  Any way to have an alternate place to store help files, 
> just as we are using an alternate location for packages? 
> 
> I tried giving users Modify permission to R..../doc/html folder.  With 
> this, install package does NOT give any error for insufficient 
> permission to install help; help(package='package_name') works; however 
> help(function, package='package_name') still does not work. 
> 
> Is there any good way out of this dilemma, short of giving users free 
> permission to the entire R installation?  Thanks for any suggestions.

I wouldn't play with the permissions.  I think you can install help 
pages locally, and as long as you set the library locations properly 
(using R_LIBS and/or .libPaths()) help should be available.  The one 
thing you can't do on Windows is link locally installed help in with 
global help.

So I'd suggest settling on a particular location for each student to put 
his or her library, e.g. R_lib under their home directory.  Then put 
"R_LIBS=/path/to/R_lib" on the command line.  The tricky bit might be 
working out what /path/to/R_lib is if it varies from student to student 
and you want to set it for them. This setting for the target in the 
shortcut seems to work for me:

"C:\Program Files\R\R-2.4.0\bin\Rgui.exe" 
R_LIBS="%HOMEDRIVE%%HOMEPATH%/R_libs"

You can run .libPaths() to check after you start, and 
Sys.getenv("R_LIBS") to see what you were asking for.  If the R_libs 
directory doesn't exist, then you won't see it in .libPaths.

Duncan Murdoch