<?php

/***********************************************************************
  webtty.php - server side script used to control and transfer data
               between server process and client webpage
  This file is part of the webtty package. Latest version can be found
  at the homepage at http://testape.com/webtty_sample.html
  The webtty package was written by Martin Steen Nielsen.
  webtty is free software; you can redistribute it and/or modify it 
  under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.
***********************************************************************/

$temp_dir="./data/webtty_log/";


/***********************************************************************
   creates a new session with a shell
 ***********************************************************************/
function virtual_shell_create( )
    {
    global $temp_dir;
    $count = 0;
    $id = md5($time . rand() );
    $cmd = "./webtty ./data/webtty_log/" . $id . " bash 2>/dev/null >&- <&- >/dev/null &";
    system($cmd); 
    /* wait until all fifo's are created */
    while ( $count<10 )
        {
	if (file_exists($temp_dir . $id . "_out"))
	     { break; }
	 sleep(1); 
	 $count++;
	};

    /* Check if we have waited to long */
    if ($count == 10)
        { return 0; }
	
    return $id;
    }



/***********************************************************************
   deletes a session - kills shell
 ***********************************************************************/
function shell_delete($id)
    {
    global $temp_dir;
    if (file_exists($temp_dir . $id . "_pid"))
        {
        $pid = file($temp_dir . $id . "_pid");
        exec ("kill " . $pid[0] );
        }
    flush();
    }
  

/***********************************************************************
   forwards data to shell
 ***********************************************************************/
function shell_put($ids, $cmd)
    {
    global $temp_dir;
    $inp = $temp_dir . $ids . "_in";
    $fil = fopen($inp, "w"); 
    fputs($fil,$cmd); 
    fclose($fil);
    flush();
    }



/***********************************************************************
   outputs data from shell
 ***********************************************************************/
function shell_get($ids)
    {
    global $temp_dir;
    
    $outp = $temp_dir . $ids . "_out";

    if (file_exists($outp))
        {             
    	readfile($outp);
        }	
    else
        {
	echo "_C_L_O_S_E_D_";
	}

    flush();
    }

/* initialize session system and close immediately to avoid hanging later */
session_start(); 
session_write_close ();

define_syslog_variables();
openlog("webtty", LOG_PID | LOG_PERROR, LOG_LOCAL0);

syslog(LOG_WARNING,$_POST['inp']);

/* get input  */
$shell=$_GET['shell'];

if (isset($_POST['id']))
  { $ids = $_POST['id']; }
else if (isset($_GET['id']))
  { $ids = $_GET['id']; }
else
  { $ids=''; }
  
$inp=(isset($_POST['inp']))?$_POST['inp']:''; 

$outp=(isset($_GET['outp']))?$_GET['outp']:''; 

syslog(LOG_WARNING,"inp=" . $inp . " outp=" . $outp . " id=" . $id );

if ( 'kill' == $shell )
    {
    shell_delete($ids);
    }
else if ( 'virt' == $shell )
    {
    $id = virtual_shell_create();
    
    /* create new process */
    if ($id != '0')
        {
        echo "<SPAN id=webtty_session_id style='display:none'>" . $id . "</SPAN>\n";
	  echo "<TEXTAREA ID=webtty_output class=webtty ></TEXTAREA>\n";
	  }
    }
else
    {
    if ($inp != '')
        {
        /* Yes - process input */
        shell_put($ids,$inp);
        } 
    else if ($outp != '' )
        {
        /* Dump the output */
        shell_get($ids); 
        }
    }