detect whether directory is empty recursively
Examples
# create an empty directory
dir.create("some/deep/path/in/a/folder", recursive = TRUE)
empty_dir("some/deep/path/in/a/folder")
#> [1] TRUE
# create an empty file
file.create("some/deep/path/in/a/folder/there_is_a_file.txt")
#> [1] TRUE
empty_dir("some/deep/path/in/a/folder")
#> [1] FALSE
empty_file("some/deep/path/in/a/folder/there_is_a_file.txt", strict = TRUE)
#> [1] TRUE
# create a file with only character of length 0
write("", "some/deep/path/in/a/folder/there_is_a_file.txt")
empty_file("some/deep/path/in/a/folder/there_is_a_file.txt", strict = TRUE)
#> [1] FALSE
empty_file("some/deep/path/in/a/folder/there_is_a_file.txt")
#> [1] TRUE
# clean
unlink("some", recursive = TRUE)