beer.R

bottles_of_beer <- function(i = 99) {
  message("There are ", i, " bottles of beer on the wall, ", i, " bottles of beer.")
  while(i > 0) {
    tryCatch(
      Sys.sleep(1),
      interrupt = function(err) {
        i <<- i - 1
        if (i > 0) {
          message(
            "Take one down, pass it around, ", i, 
            " bottle", if (i > 1) "s", " of beer on the wall."
          )
        }
      }
    )
  }
  message("No more bottles of beer on the wall, no more bottles of beer.")
}

bottles_of_beer()