http://www.jcraft.com/jsch/: JSch is a pure Java implementation of SSH2 (JCraft,Inc.) 
/* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
/*
Copyright (c) 2002-2018 ymnk, JCraft,Inc. All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

  1. Redistributions of source code must retain the above copyright notice,
     this list of conditions and the following disclaimer.

  2. Redistributions in binary form must reproduce the above copyright 
     notice, this list of conditions and the following disclaimer in 
     the documentation and/or other materials provided with the distribution.

  3. The names of the authors may not be used to endorse or promote products
     derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,
INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

package com.jcraft.jsch;

import java.util.*;

class ChannelSession extends Channel{
  private static byte[] _session=Util.str2byte("session");

  protected boolean agent_forwarding=false;
  protected boolean xforwading=false;
  protected Hashtable env=null;

  protected boolean pty=false;

  protected String ttype="vt100";
  protected int tcol=80;
  protected int trow=24;
  protected int twp=640;
  protected int thp=480;
  protected byte[] terminal_mode=null;

  ChannelSession(){
    super();
    type=_session;
    io=new IO();
  }

  
Enable the agent forwarding.

Params:
  • enable – 
/**
   * Enable the agent forwarding.
   *
   * @param enable
   */
  public void setAgentForwarding(boolean enable){ 
    agent_forwarding=enable;
  }

  
Enable the X11 forwarding.
Refer to RFC4254 6.3.1. Requesting X11 Forwarding.

Params:
  • enable – 
/**
   * Enable the X11 forwarding.
   * Refer to RFC4254 6.3.1. Requesting X11 Forwarding.
   *
   * @param enable
   */
  public void setXForwarding(boolean enable){
    xforwading=enable; 
  }

  
See Also:
Deprecated:Use setEnv(String, String) or setEnv(byte[], byte[]) instead.
/**
   * @deprecated Use {@link #setEnv(String, String)} or {@link #setEnv(byte[], byte[])} instead.
   * @see #setEnv(String, String)
   * @see #setEnv(byte[], byte[])
   */
  public void setEnv(Hashtable env){ 
    synchronized(this){
      this.env=env; 
    }
  }

  
Set the environment variable. 
If name and value are needed to be passed to the remote in your favorite encoding, use setEnv(byte[], byte[]). Refer to RFC4254 6.4 Environment Variable Passing. 
Params:
  • name – A name for environment variable.
  • value – A value for environment variable.
/**
   * Set the environment variable. 
   * If <code>name</code> and <code>value</code> are needed to be passed 
   * to the remote in your favorite encoding,
   * use {@link #setEnv(byte[], byte[])}.
   * Refer to RFC4254 6.4 Environment Variable Passing.
   *
   * @param name A name for environment variable.
   * @param value A value for environment variable.
   */
  public void setEnv(String name, String value){
    setEnv(Util.str2byte(name), Util.str2byte(value));
  }

  
Set the environment variable.
Refer to RFC4254 6.4 Environment Variable Passing.

Params:
  • name – A name of environment variable.
  • value – A value of environment variable.
See Also:
/**
   * Set the environment variable.
   * Refer to RFC4254 6.4 Environment Variable Passing.
   *
   * @param name A name of environment variable.
   * @param value A value of environment variable.
   * @see #setEnv(String, String)
   */
  public void setEnv(byte[] name, byte[] value){
    synchronized(this){
      getEnv().put(name, value);
    }
  }

  private Hashtable getEnv(){
    if(env==null)
      env=new Hashtable();
    return env;
  }

  
Allocate a Pseudo-Terminal.
Refer to RFC4254 6.2. Requesting a Pseudo-Terminal.

Params:
  • enable – 
/**
   * Allocate a Pseudo-Terminal.
   * Refer to RFC4254 6.2. Requesting a Pseudo-Terminal.
   *
   * @param enable
   */
  public void setPty(boolean enable){ 
    pty=enable; 
  }

  
Set the terminal mode.

Params:
  • terminal_mode – 
/**
   * Set the terminal mode.
   * 
   * @param terminal_mode
   */
  public void setTerminalMode(byte[] terminal_mode){
    this.terminal_mode=terminal_mode;
  }

  
Change the window dimension interactively.
Refer to RFC4254 6.7. Window Dimension Change Message.

Params:
  • col – terminal width, columns
  • row – terminal height, rows
  • wp – terminal width, pixels
  • hp – terminal height, pixels
/**
   * Change the window dimension interactively.
   * Refer to RFC4254 6.7. Window Dimension Change Message.
   *
   * @param col terminal width, columns
   * @param row terminal height, rows
   * @param wp terminal width, pixels
   * @param hp terminal height, pixels
   */
  public void setPtySize(int col, int row, int wp, int hp){
    setPtyType(this.ttype, col, row, wp, hp);
    if(!pty || !isConnected()){
      return;
    }
    try{
      RequestWindowChange request=new RequestWindowChange();
      request.setSize(col, row, wp, hp);
      request.request(getSession(), this);
    }
    catch(Exception e){
      //System.err.println("ChannelSessio.setPtySize: "+e);
    }
  }

  
Set the terminal type.
This method is not effective after Channel#connect().

Params:
  • ttype – terminal type(for example, "vt100")
See Also:
/**
   * Set the terminal type.
   * This method is not effective after Channel#connect().
   *
   * @param ttype terminal type(for example, "vt100")
   * @see #setPtyType(String, int, int, int, int)
   */
  public void setPtyType(String ttype){
    setPtyType(ttype, 80, 24, 640, 480);
  }

  
Set the terminal type.
This method is not effective after Channel#connect().

Params:
  • ttype – terminal type(for example, "vt100")
  • col – terminal width, columns
  • row – terminal height, rows
  • wp – terminal width, pixels
  • hp – terminal height, pixels
/**
   * Set the terminal type.
   * This method is not effective after Channel#connect().
   *
   * @param ttype terminal type(for example, "vt100")
   * @param col terminal width, columns
   * @param row terminal height, rows
   * @param wp terminal width, pixels
   * @param hp terminal height, pixels
   */
  public void setPtyType(String ttype, int col, int row, int wp, int hp){
    this.ttype=ttype;
    this.tcol=col;
    this.trow=row;
    this.twp=wp;
    this.thp=hp;
  }

  protected void sendRequests() throws Exception{
    Session _session=getSession();
    Request request;
    if(agent_forwarding){
      request=new RequestAgentForwarding();
      request.request(_session, this);
    }

    if(xforwading){
      request=new RequestX11();
      request.request(_session, this);
    }

    if(pty){
      request=new RequestPtyReq();
      ((RequestPtyReq)request).setTType(ttype);
      ((RequestPtyReq)request).setTSize(tcol, trow, twp, thp);
      if(terminal_mode!=null){
        ((RequestPtyReq)request).setTerminalMode(terminal_mode);
      }
      request.request(_session, this);
    }

    if(env!=null){
      for(Enumeration _env=env.keys(); _env.hasMoreElements();){
        Object name=_env.nextElement();
        Object value=env.get(name);
        request=new RequestEnv();
        ((RequestEnv)request).setEnv(toByteArray(name), 
                                     toByteArray(value));
        request.request(_session, this);
      }
    }
  }

  private byte[] toByteArray(Object o){
    if(o instanceof String){
      return Util.str2byte((String)o);
    }
    return (byte[])o;
  }

  public void run(){
    //System.err.println(this+":run >");

    Buffer buf=new Buffer(rmpsize);
    Packet packet=new Packet(buf);
    int i=-1;
    try{
      while(isConnected() &&
	    thread!=null && 
            io!=null && 
            io.in!=null){
        i=io.in.read(buf.buffer, 
                     14,    
                     buf.buffer.length-14
                     -Session.buffer_margin
		     );
	if(i==0)continue;
	if(i==-1){
	  eof();
	  break;
	}
	if(close)break;
        //System.out.println("write: "+i);
        packet.reset();
        buf.putByte((byte)Session.SSH_MSG_CHANNEL_DATA);
        buf.putInt(recipient);
        buf.putInt(i);
        buf.skip(i);
	getSession().write(packet, this, i);
      }
    }
    catch(Exception e){
      //System.err.println("# ChannelExec.run");
      //e.printStackTrace();
    }
    Thread _thread=thread; 
    if(_thread!=null){
      synchronized(_thread){ _thread.notifyAll(); }
    }
    thread=null;
    //System.err.println(this+":run <");
  }
}