Re: [R] Test internet presence

From: Gregor Gorjanc <gregor.gorjanc_at_bfro.uni-lj.si>
Date: Mon 11 Sep 2006 - 22:49:10 GMT

Prof Brian Ripley <ripley <at> stats.ox.ac.uk> writes: ...
> Check out tests/internet.R. nsl() checks if you can resolve host names,
> which has worked well enough there.

Thank you prof. Ripley for this pointer. I am posting here the relevant part if someone does not look at SVN. I would just like to ask why is .Platform$OS.type == "unix" added to the test? Is nsl() available only on unix like platforms or ... I did not found any specifics in its help page.

if(!capabilities()["http/ftp"]) {

    warning("no internet capabilities")
    q()
}

if(.Platform$OS.type == "unix" &&

   is.null(nsl("cran.r-project.org"))) q()

Does it make any sense to write a function that would use these two tests.

isNetAvailable <- function()
{
  ifelse(!capabilities()["http/ftp"] &&

##         .Platform$OS.type == "unix" && ## ??? 
         is.null(nsl("cran.r-project.org")), 
         FALSE, 
         TRUE)

}

Regards, Gregor



R-help@stat.math.ethz.ch mailing list
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. Received on Tue Sep 12 16:15:38 2006

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.1.8, at Tue 12 Sep 2006 - 16:27:52 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.