zprint-filter.sh

#!/bin/bash

abs_bin_dir="$(cd "$(dirname "$0")" && pwd)"
FILE="${abs_bin_dir}/zprint-filter-0.4.4"

# check if zprint server port is reachable
ncat -z 127.0.0.1 7877

if [ $? == 0 ]; then
    ncat 127.0.0.1 7877 <&0
else
    if [ -f $FILE ]; then
        java -Xbootclasspath/a:$FILE zprint.main '{:style :community}' <&0
    else
        curl --location --silent --output $FILE "https://github.com/kkinnear/zprint/releases/download/0.4.4/zprint-filter-0.4.4"
        java -Xbootclasspath/a:$FILE zprint.main '{:style :community}' <&0
    fi
fi

zprint_server.clj

(ns server.zprint-server
  (:require [zprint.core :as zprint]
            [clojure.java.io :as io])
  (:import [java.net InetAddress Socket ServerSocket SocketException]))

(defmacro ^:private thread
  [^String name daemon & body]
  `(doto (Thread. (fn [] ~@body) ~name)
    (.setDaemon ~daemon)
    (.start)))

(defn- read-all-lines [in]
  (let [sw (java.io.StringWriter.)]
      (io/copy in sw)
      (.toString sw)))

(defn- accept-connection
  "Start accept function, to be invoked on a client thread, given:
    conn - client socket
    in - in stream
    out - out stream
    err - err stream"
  [^Socket conn in out err]
  (let [contents (read-all-lines in)]
    (try (spit out (zprint/zprint-file-str contents "<stdin>"))
         (catch clojure.lang.ExceptionInfo e (spit out contents))
         (catch SocketException _disconnect)
         (finally (.close conn)))))

(defn start-server
  "Start a zprint server given the specified opts:
    :address Host or address, string, defaults to loopback address
    :port Port, integer, required
    :bind-err Bind *err* to socket out stream?, defaults to true
   Returns a socket."
  [opts]
  (let [{:keys [address port bind-err]
         :or {bind-err true}} opts
         address (InetAddress/getByName address)  ;; nil returns loopback
         socket (ServerSocket. port 0 address)]
    (thread
      (str "zprint Server ")
      true
      (try
        (loop [client-counter 1]
          (when (not (.isClosed socket))
            (try
              (let [conn (.accept socket)
                    in (.getInputStream conn)
                    out (java.io.BufferedWriter. (java.io.OutputStreamWriter. (.getOutputStream conn)))
                    client-id (str client-counter)]
                (thread
                  (str "zprint client " client-counter)
                  true
                  (accept-connection conn in out (if bind-err out *err*))))
              (catch SocketException _disconnect))
            (recur (inc client-counter))))))

    socket))