drops all messages older than some date from a textsecure backup

textsecure_cutoff.clj

(def cutoff
  (clj-time.coerce/to-long
    (clj-time.core/date-time 2015 4 3 5 54)))

(with-open [input (java.io.FileInputStream.
                    "/Users/michael.blume/TextSecurePlaintextBackup.xml")
            output (java.io.FileWriter.
                     "/Users/michael.blume/betterbackup.xml")]
  (-> input
      clojure.data.xml/parse
      (update-in [:content] (fn [messages]
                              (filter #(-> % :attrs :date Long/parseLong (> cutoff)) messages)))
      (clojure.data.xml/emit output)
      ))