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

As the function above from eyjo

havingIP <- function() {
 if (.Platform$OS.type == "windows") {
   ipmessage <- system("ipconfig", intern = TRUE)
 } else {
   ipmessage <- system("ifconfig", intern = TRUE)
 }
 validIP <- "((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)[.]){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)"
 any(grep(validIP, ipmessage))
}

also returns true for localhost ip "127.0.0.1" it needs to be removed to prevent false positives. For example as shown below:

 havingIP <- function() {
 if (.Platform$OS.type == "windows") {
   ipmessage <- system("ipconfig", intern = TRUE)
 } else {
   ipmessage <- system("ifconfig", intern = TRUE)
 }
 validIP <- "((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)[.]){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)"
 any(grep(validIP, ipmessage[-grep("127.0.0.1", ipmessage)]))
}

But even better would be a solution that prevents localhosts by modifying the regex of validIP.