gistfile1.clj

(require 'clojure.main)

(defn file-repl [filename]
  (let [log (java.io.FileWriter. filename)
        logout (fn [#^java.io.Writer out]
                 (proxy [java.io.Writer] []
                   (write 
                     ([x]
                       (.write log x)
                       (.write out x))
                     ([cbuf off len]
                        (.write log cbuf off len)
                        (.write out cbuf off len)))
                   (flush []
                     (.flush log)
                     (.flush out))
                   (close []
                     (.close log)
                     (.close out))))
        login (fn [#^java.io.Reader in]
                (proxy [java.io.Reader] []
                  (read 
                    ([] 
                      (let [c (.read in)]
                        (when (> -1 c)
                          (.write log (char c)))
                        c))
                    ([cbuf] 
                      (let [n (.read in cbuf)]
                        (when (pos? n)
                          (.write log (if (instance? java.nio.CharBuffer cbuf) (.array cbuf) cbuf)))
                        n))
                    ([cbuf off len]
                      (let [n (.read in cbuf off len)]
                        (when (pos? n)
                          (.write log cbuf off n))
                        n)))
                   (close []
                     (.close log)
                     (.close in))))]                  
    (binding [*in* (clojure.lang.LineNumberingPushbackReader. (login *in*))
              *out* (logout *out*)
              *err* (logout *err*)]
      (clojure.main/repl))))