gistfile1.clj

(defn- wildcard-filter
  "Given a regex, return a FilenameFilter that matches."
  [re]
  (reify java.io.FilenameFilter
    (accept [_ dir name] (not (nil? (re-find re name))))))

(defn- directory-list
  "Given a directory and a regex, return a sorted seq of matching filenames."
  [dir re]
  (sort (.list (clojure.java.io/file dir) (wildcard-filter re))))