Read/write input/output stream of interactive process

gistfile1.java

import java.io.*;

public class TestProcessIO {

  public static boolean isAlive(Process p) {
    try {
      p.exitValue();
      return false;
    }
    catch (IllegalThreadStateException e) {
      return true;
    }
  }

  public static void main(String[] args) throws IOException {
    ProcessBuilder builder = new ProcessBuilder("bash", "-i");
    builder.redirectErrorStream(true); // so we can ignore the error stream
    Process process = builder.start();
    InputStream out = process.getInputStream();
    OutputStream in = process.getOutputStream();

    byte[] buffer = new byte[4000];
    while (isAlive(process)) {
      int no = out.available();
      if (no > 0) {
        int n = out.read(buffer, 0, Math.min(no, buffer.length));
        System.out.println(new String(buffer, 0, n));
      }

      int ni = System.in.available();
      if (ni > 0) {
        int n = System.in.read(buffer, 0, Math.min(ni, buffer.length));
        in.write(buffer, 0, n);
        in.flush();
      }

      try {
        Thread.sleep(10);
      }
      catch (InterruptedException e) {
      }
    }

    System.out.println(process.exitValue());
  }
}

As seen http://stackoverflow.com/a/5283096/395921

See also http://stackoverflow.com/q/4179052/395921

Dude, do you know how to get the handle to the external process and continuously read and write to it? . I am trying to communicate with a database client. I can establish a connection but could not write to it after the first read

It helped

This is what exactly I was looking for. Thanks 👍