How to obtain a list of directories within a directory, like list.files(), but instead “list.dirs()”

Question

This may be a very easy question for someone - I am able to use list.files() to obtain a list of files in a given directory, but if I want to get a list of director

Answer 1

I had this problem a while back and used this recursive code to find all directories. Perhaps this can be of use?

list.dirs <- function(parent=".")   # recursively find directories
{
    if (length(parent)>1)           # work on first and then rest
        return(c(list.dirs(parent[1]), list.dirs(parent[-1])))
    else {                          # length(parent) == 1
        if (!is.dir(parent))
            return(NULL)            # not a directory, don't return anything
        child <- list.files(parent, full=TRUE)
        if (!any(is.dir(child)))
            return(parent)          # no directories below, return parent
        else 
            return(list.dirs(child))    # recurse
    }
}

is.dir <- function(x)    # helper function
{
    ret <- file.info(x)$isdir
    ret[is.na(ret)] <- FALSE
    ret
}