logical test if object is a directory

Question

Let's say I just created this directory and file:

dir.create("foo")
cat("bar", file="bar")

#both files exist:

file.exists("foo")
file.exists("bar")

I want to test both foo and bar to test logically if they are directories or not. If something is a directory I want to be able to put other files in it. If the item is not a directory I want to use stop but don't know of how test.

Poking around a bit got me to:

file.info("foo", "bar")
.Internal(file.info(fn <- c("foo", "bar")))

Which both give me the info I'm after but the .Internal use seems to be using a logical test of sorts for directory (meaning more efficient), but I can't figure out how. What is file.info using to test if the object is a directory?

Answer 1

Maybe you want file_test?

file_test("-d", c("foo", "bar"))
# [1]  TRUE FALSE

Answer 2

file.info is obviously platform dependent and uses _wstati64 on Windows and stat on Linux. See https://svn.r-project.org/R/trunk/src/main/platform.c