R/isConnected.R

In hockeystick: Download and Visualize Essential Climate Change Data

## This function has been provided by Dirk Eddelbuettel's tint package
## https://github.com/eddelbuettel/tint/blob/master/R/isConnected.R
## It's purpose is to check for internet connectivity.
##
##
## borrowed from our dang package, but made internal here, in order to not have
## to declare a dependency for just these few lines of code
##
## Copyright Dirk Eddelbuettel
## Licensed as GPL (>= 2)
## https://cran.r-project.org/package=dang

.isConnected <- function(site="https://www.google.com") {
  uoc <- function(site) {
    con <- url(site)                # need to assign so that we can close
    open(con)                       # in case of success we have a connection
    close(con)                      # ... so we need to clean up
  }
  suppressWarnings(!inherits(try(uoc(site), silent=TRUE), "try-error"))
}