NEERC/central/run2.java

   1 import java.util.Arrays;
   2 import java.io.*;
   3
   4 /**
   5  * Simple tool to start two processes piped into each other.
   6  *
   7  * @author Roman Elizarov
   8  */
   9 public class run2 {
  10         public static void main(String[] args) throws IOException, InterruptedException {
  11                 if (args.length < 2) {
  12                         System.err.println("Usage: run2 <interaction-exe> <main-exe> [<main-process-args> ...]");
  13                         return;
  14                 }
  15                 run2 instance = new run2(args);
  16                 try {
  17                         instance.go();
  18                 } finally {
  19                         instance.killThemAll();
  20                 }
  21         }
  22
  23         private final Process p1;
  24         private final Process p2;
  25
  26         private run2(String[] args) throws IOException {
  27                 ProcessBuilder pb1 = new ProcessBuilder(args[0]);
  28                 ProcessBuilder pb2 = new ProcessBuilder(Arrays.asList(args).subList(1, args.length).toArray(new String[args.length - 1]));
  29                 pb1.redirectErrorStream(true);
  30                 pb2.redirectErrorStream(true);
  31                 p1 = pb1.start();
  32                 p2 = pb2.start();
  33         }
  34
  35         private void go() throws InterruptedException {
  36                 new Redirector(p1.getInputStream(), p2.getOutputStream()).start();
  37                 new Redirector(p2.getInputStream(), p1.getOutputStream()).start();
  38                 p2.waitFor();
  39                 p1.destroy();
  40                 p1.waitFor();
  41         }
  42
  43         private void killThemAll() {
  44                 p1.destroy();
  45                 p2.destroy();
  46         }
  47
  48         private class Redirector extends Thread {
  49                 final InputStream in;
  50                 final OutputStream out;
  51
  52                 private Redirector(InputStream in, OutputStream out) {
  53                         this.in = in;
  54                         this.out = out;
  55                 }
  56
  57                 public void run() {
  58                         byte[] buf = new byte[4096];
  59                         int len;
  60                         try {
  61                                 while ((len = in.read(buf)) > 0) {
  62                                         out.write(buf, 0, len);
  63                                         out.flush();
  64                                 }
  65                         } catch (IOException e) {
  66                                 System.err.println(e.toString());
  67                                 killThemAll();
  68                         }
  69                 }
  70         }
  71 }