How to determine if you have an internet connection in R

Question

Sometimes I need to download data from the internet. On occasions this has failed either because the website is down or because my computer has lost its internet connection.

Question: Is there some function in R which will return TRUE/FALSE as to whether I am connected to the internet?

Answer 1

The curl package has a function has_internet which tests by performing a nslookup:

curl::has_internet ## function(){ ##    !is.null(nslookup("google.com", error = FALSE)) ## } 

Testing DNS is faster and may be more reliable than retrieving a URL because the latter might fail for unrelated reasons (e.g. firewall, server down, etc).

Answer 2

A dirty work around would be using RCurl::getURL function.

if (is.character(getURL("www.google.com"))) {     out <- TRUE } else {     out <- FALSE }