Thank you very much, Michael! That was exactly the hint I needed. I ended up using "try" as below, in case anyone happens to read this later on... Works perfectly fine. So yes, it _is_ amazing, what one can do with R ;-)
Regards, Berry internet <- try(read.table("http://www..."), silent=T ) if(!class(internet)=="try-error") { # take subset and write into file } else { cat("connection not successfull\n") } > CC: r-help@r-project.org > From: michael.weyla...@gmail.com > Subject: Re: [R] check whether connection can be opened > Date: Wed, 18 Jul 2012 09:18:48 -0500 > To: berryboessenk...@hotmail.com > > I think you'll need to roll your own using tryCatch() around open(). > > Michael > > On Jul 18, 2012, at 5:09 AM, Berry Boessenkool <berryboessenk...@hotmail.com> > wrote: > > > > > > > Hi all, > > > > I'm working on a function that reads online data that is only available to > > certain IPs. It then writes a subset of the data into a file. > > So whenever I'm logged in elsewhere or am not connected to the internet, I > > get an error, and the function is terminated. > > I want it to rather print a message into the file. > > > > Is there any way to test whether a connection can be opened? > > Analogous to isOpen something like canOpen... > > Or would I want to look into the error handling options? > > > > By the way, the data is the internet volume used so far, which I want to > > track regularly (on every R-Start via Rprofile). > > My brother (a computer schientist in progress) did not know a solution, so > > I set out to try this with R - which I got to work fine (except the above > > mentioned). > > "R beats java", I told him, to which he responded nothing ;-) > > Isn't it amazing, what one can do with R? > > > > Thanks ahead, > > Berry Boessenkool > > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org 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.