[R] cannot dyn.load dll from path

[Duncan Murdoch]

On 19/01/2012 1:42 PM, Adrian Dragulescu wrote:
> It doesn't work even if I set it with \\.  My path has a mixture of \\ and
> / and other entries work fine.
>
> if (file.exists("C:/Temp/XML.dll")) {
>     Sys.setenv(path = paste("C:\\Temp;C:/Temp;", Sys.getenv("path"), sep=""))
>     dyn.load("XML.dll")   # doesn't find it!
> }
> Error in inDL(x, as.logical(local), as.logical(now), ...) :
>     unable to load shared object '//nas-msw-20/adrian/My Documents/XML.dll':
>     LoadLibrary failure:  The specified module could not be found.
> >
>
> My home folder is on a network drive.

I really think you should follow the advice in ?dyn.load and use a full 
path, or go to Microsoft's site and check the rules for how LoadLibrary 
searches for DLLs.

Duncan Murdoch

> Thank you,
> Adrian
>
>
>
> On Thu, 19 Jan 2012, Duncan Murdoch wrote:
>
> >  On 19/01/2012 11:19 AM, Adrian Dragulescu wrote:
> >>  Hello,
> >>
> >>  I'm on Windows, and according to the documentation R searches along the
> >>  search path when looking for dll's for dyn.load.
> >>
> >>  For illustration, I've copied the XML.dll from package XML in the C:/Temp
> >>  folder
> >>
> >>      if (file.exists("C:/Temp/XML.dll")) {
> >>        Sys.setenv(path = paste("C:/Temp;", Sys.getenv("path"), sep=""))
> >>        dyn.load("XML.dll")   # doesn't find it!
> >>      }
> >>
> >>
> >>      head(strsplit(Sys.getenv("path"), ";")[[1]])  # C:/Temp is there
> >>
> >>      dyn.load("C:/Temp/XML.dll")  # works fine
> >>
> >>  Am I misreading the documentation?
> >
> >  I believe that search is done by Windows, and different versions are very
> >  inconsistent about search order.  However, one thing I would guess is that
> >  recent versions would require backslashes rather than forward slashes in
> >  PATH.  When R gets a path, it generally translates the slashes, but if you're
> >  relying on Windows to do it, you're stuck with what they decide to do.
> >
> >  Duncan Murdoch
> >