gistfile1.clj

(defn serve-file
  "Attempts to serve up a static file from a directory, which defaults to
  './public'. Nil is returned if the file does not exist. If the file is a
  directory, the function looks for a file in the directory called 'index.*'."
  ([path]
    (serve-file "public" path))
  ([root path]
    (let [filepath (File. root path)]
      (if (safe-path? root path)
        (cond 
          (.isFile filepath)
            filepath
          (.isDirectory filepath)
            (find-index-file filepath))))))