title: "tail -f" process will not exit after JSch connection closed
body: <p>I used JSch to tail a file in remote computer. But I found that after the program exit, 
  the "tail -f" process is still there in remote computer. 
  if I remove the "-f" param, everything is OK.</p>
  
  <p>I've tried to use "sendSignal()", but it not work. it seems the function is not implemented by OpenSSH. </p>
  
  <p>Here is the testing code. </p>
  
  <pre><code>public static void main(String[] args) throws Exception {
      String usr = args[0];
      String host = args[1];
      String password = args[2];
      JSch jsch = new JSch();
      Session session = jsch.getSession(usr, host);
      String pwd = password;
      session.setPassword(pwd);
      Hashtable&lt;String, String&gt; config = new Hashtable&lt;String, String&gt;();
      config.put("StrictHostKeyChecking", "no");
      session.setConfig(config);
      session.connect(15000);
      session.setServerAliveInterval(15000);
  
  
      ChannelExec m_channelExec = (ChannelExec) session.openChannel("exec");
      String cmd = "tail -f /var/log/messages";
      m_channelExec.setCommand(cmd);
      InputStream m_in = m_channelExec.getInputStream();
      m_channelExec.connect();
      BufferedReader m_bufferedReader = new BufferedReader(new InputStreamReader(m_in));
      int i = 0;
      while (++i &lt; 10) {
  
          if (m_bufferedReader.ready()) {
              String line = m_bufferedReader.readLine();
              System.out.println(line);
          }
          Thread.sleep(1000);
      }
      m_bufferedReader.close();
      m_channelExec.sendSignal("SIGINT");
      m_channelExec.disconnect();
      session.disconnect();
      System.out.println("exit");
  }
  </code></pre>
  
  <p>Is there any solution to fix this problem?</p>