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.

Answer 1

All these answers use packages or code outside of base R. Here's how to do it with just base R:

# IANA's test website
is_online <- function(site="http://example.com/") {
  tryCatch({
    readLines(site,n=1)
    TRUE
  },
  warning = function(w) invokeRestart("muffleWarning"),
  error = function(e) FALSE)
}