Split a file path into folder names vector

Question

In R, with file.path, you can convert a character vector into a full file path, automatically using the correct file separator for your platform :

> file.path("home", "foo", "script.R")
[1] "home/foo/script.R"

I'd like to do exactly the reverse : split a file path into a character vector of components. So far I almost manage to do it with a recursive function, but I don't find it very elegant :

split_path <- function(file) {
  if(!(file %in% c("/", "."))) {
    res <- c(basename(file), split_path(dirname(file)))
    return(res)
  }
  else return(NULL)
}

Which gives :

> split_path("/home/foo/stats/index.html")
[1] "index.html" "stats"      "foo"        "home" 

Do you know of any already existing function, or at least a better way to do such a thing ?

Thanks !

EDIT : I think I'll finally stick to this slightly different recursive version, thanks to @James, which should handle drive letters and network shares under Windows :

split_path <- function(path) {
  if (dirname(path) %in% c(".", path)) return(basename(path))
  return(c(basename(path), split_path(dirname(path))))
}

Answer 1

Try this (will work with both "/" and "\"):

split_path <- function(path) {
    rev(setdiff(strsplit(path,"/|\\\\")[[1]], ""))
} 

Results

split_path("/home/foo/stats/index.html")
# [1] "index.html" "stats"      "foo"        "home"

rev(split_path("/home/foo/stats/index.html"))
# [1] "home"       "foo"        "stats"      "index.html"

Edit

Making use of normalizePath, dirname and basename, this version will give different results:

split_path <- function(path, mustWork = FALSE, rev = FALSE) {
    output <- c(strsplit(dirname(normalizePath(path,mustWork = mustWork)),
                                             "/|\\\\")[[1]], basename(path))
    ifelse(rev, return(rev(output)), return(output))
}

split_path("/home/foo/stats/index.html", rev=TRUE)
# [1] "index.html" "stats"      "foo"        "home"       "D:"