使用php proc_open的八度交互式shell

时间:2018-05-31 13:05:30

标签: php octave

我正在编写一个要在apache下执行的PHP代码(不幸的是在Windows操作系统下使用xampp PHP 7.2.x)。 PHP脚本应该以交互方式调用八度音阶,以便能够按顺序执行更多命令,而无需为每个命令创建专用的八度音程。

下面是一个PHP脚本示例。

我的交互式工作模式有问题;我的意思是,我能够执行一个八度音阶并返回结果,但我无法按顺序发送几个八度音命令。

<?php

    $descriptorspec = array(
               0 => array("pipe", "r"),  // stdin is a pipe that the child will read from
               1 => array("pipe", "w"),  // stdout is a pipe that the child will write to
               2 => array("pipe", "w")   // stderr is a pipe that the child will write to, you can specify a file as well
            );

    $octave = 'C:\Octave\Octave-4.4.0\bin\octave-cli-4.4.0 ';

    $cmd = $octave . ' --no-gui -i  -q --eval disp(10)';

    $process = proc_open($cmd, $descriptorspec, $pipes);

    if (!is_resource($process)) {
        die("PROCESS CREATION ERROR CMD: $cmd");
    }

    $str = "eval('disp(20)');\r\n" . chr(13);
    if(fwrite($pipes[0],$str) === false){
        die("fwrite ERROR");
    }

    $str = stream_get_contents($pipes[1]);
    if($str === false){
        die("stream_get_contents ERROR");
    }else{
        echo $str;
    }

    fclose($pipes[0]);
    fclose($pipes[1]);

$return_value = proc_close($process);

    echo "command returned $return_value\n";
?>

在这种情况下,输出为:10个命令返回0

相反,如果定义$ cmd = $ octave。 &#39; --no-gui -i -q&#39;;

脚本被阻止,等待返回的包机到stream_get_contents。使用fgets的结果相同。

我的理解是,八度音不能正确接收fwrite命令,因此它不会打印结果(即使fwrite没有返回任何错误)。也许问题是由于代码要作为回车发送,以告诉八度执行代码。此外,目前尚不清楚,我是否应该使用eval函数或只是编写命令。然而,在所有尝试中,没有任何改变。

有什么想法吗?

2 个答案:

答案 0 :(得分:0)

在下面的代码审查中,如果有用的话,可以工作。 我还创建了一个专用的类(octave_stream),以提供一个接口,例如,允许html页面按需启动专用的octave进程(使用SSE通信),然后作为ajax请求逐个发送命令。每当用户离开页面或在未使用的时间之后,sw都会关闭八度音程。

下面是基于以下4个文件的整个代码:octave.php,octave_sse.php,octave_com.php。

octave.php

<?php

class octave {

private $pipes = null;
private $process = null;

private $add_semicolon = false;

private $debug = false;
private $print = false;

function __destruct() {
    $this->close_octave();
}   

public function close_octave(){
    if ($this->pipes !== null){
        fclose($this->pipes[0]);
        fclose($this->pipes[1]);
        $return_value = proc_close($this->process);
        if($this->debug){ echo "command returned $return_value<br>";}
        return $return_value;
    }   
    return false;
}   

public function open_octave(){

    $dir = sys_get_temp_dir();
    $error_file_name = tempnam($dir, "npt");
    $descriptorspec = array(
               0 => array("pipe", "rb"),  // stdin is a pipe that the child will read from
               1 => array("pipe", "wb"),  // stdout is a pipe that the child will write to
               2 => array("file", $error_file_name,"a")   // stderr:: you HAVE TO specify a file 
            );

    $octave = 'C:\Octave\Octave-4.4.0\bin\octave-cli-4.4.0 ';

    $cmd = $octave . ' --no-gui -i  -q';

    $pipes = array();

    $this->process = proc_open($cmd, $descriptorspec, $pipes);
    if (!is_resource($this->process)) {
        echo "PROCESS CREATION ERROR CMD: $cmd";
        return false;
    }

    if (count($pipes) == 0){
        echo 'pipes: '; var_dump($pipes); echo '<br>';
        echo "PROCESS CREATION ERROR CMD: $cmd";
        return false;
    }

    //stream_set_blocking($pipes[1],false); // doesn't work on STDIN  / OUT

    $this->pipes = $pipes;

    $cmd_id = 0;
    $this->read($cmd_id);
    return true;
} //end open_octave

private function raw_read(){
    $str = fread($this->pipes[1],8192); 

    if($str === false){
        echo '<br>'. __FUNCTION__ . ' fgets ERROR for CMD: ' . htmlentities($cmd);
        return false;
    }   


    //echo "READ: $str<br>";
    return $str;

} //end read


private function read(&$cmd_num){

    $result = '';

    $string = $this->raw_read();

    if($this->debug){echo '<br>' . __FUNCTION__ . ' RAW_READ1: ' . $string;  }

    if($string[0] == '>'){
        //special case, multiple line statement
        if($this->debug){echo '<br>' . __FUNCTION__ . ' multiple line statement.' ;  }
        $cmd_num = -1;
        return '';
    }   

    $tok = strtok($string, "octave:");

    while (($tok === false) || ($tok == $string)) {
        //the response do not conatin the promt; therefore, other rows are coming, read them as well and concatenate to the current response
        $result .=  $string;
        usleep(100); 
        $string = $this->raw_read();
        if($this->debug){echo '<br>' . __FUNCTION__ . ' RAW_READ NEXT: ' . $string;  }
        $tok = strtok($string, "octave:");
    }

    $cmd_num = -1;

    //in this case string include the promt; nothing more to be read. tok is the string without the "ocatve:" but you still have the 'num>' to be removed.
    $allTheRest = strtok( '' ); 
    if(($allTheRest === false) ||  ($allTheRest == '')){
        //tok has the promt rest
        list($cmd_num) = sscanf($tok,'%u>');
    }else{
        $result .= $tok;
        list($cmd_num) = sscanf($allTheRest,'ctave:%u>');
    }

    if($this->debug){echo '<br>' . __FUNCTION__ . " RAW_READ TOK: '$tok' STRING: '$string' RESULT: '$result'  allTheRest: '$allTheRest' cmd_num: $cmd_num ## ";  }

    return $result;
}   



//return the command answer removing the promt. Therefore, in case no retrun message command an empty string is given
public function octave_cmd($cmd,&$cmd_num){
    if($this->add_semicolon){
        $last_chr = strlen($cmd) - 1;
        if(substr($cmd, $last_chr, 1) != ';'){
            $cmd = $cmd . ';'; // adding ; at the input command  required by octave
        }
    }

    //echo "$cmd<br>";exit(0);

    $cmd = $cmd . PHP_EOL ;// "\r\n"
    if(fwrite($this->pipes[0],$cmd) === false){
        echo '<br>'. __FUNCTION__ . ' fwrite ERROR for CMD: ' . htmlentities($cmd);
        return false;
    }


    //usleep(100); // needed when more output row are given ... without this you read before the progam write the next row ... and you lost it ... a nice solution anyway should be to read again unil you find the promt that is always the latest given.



    $ret = $this->read($cmd_num);

    if($this->print){
        echo "<br>COMMAND # $cmd_num: " .htmlentities($cmd) . (($ret != '')?(' RESULT: ' . nl2br(htmlentities($ret))):'') . ' END<br>';
    }

    return $ret;

}

public function print_cmd($cmd){
    $cmd_id = 0;

    $ret = $this->octave_cmd($cmd,$cmd_id);

    echo "<br>COMMAND # $cmd_id: " .htmlentities($cmd) . (($ret != '')?(' RESULT: ' . nl2br(htmlentities($ret))):'') . ' END<br>';
}   
}   

class octave_stream {

private $address = 'tcp://127.0.0.1';
private $port = 5454;

private $errno = 0;
private $errstr = '';

private $server_istance = false;
private $sse = false;

/*This function start octave process, open a tcp connection and waits for incoming commands.
(to send the commands use the func. send_cmd)
Each command received is forwared to octave and the ocatve answer is forwared to who sent the command.
To stop the server a special command has to be sent. The caller has to use the stop_server()
*/
public function create_server($accept_max_retray = 30){

    $this->server_istance = true; // first command to be done

    $available_port = $this->find_usable_listening_port($this->port);
    if($available_port === false){
        $this->server_log('NOT FOUND AN AVAILABLE PORT TO START THE LISTENING SERVER');
        return false;
    }else{
        $this->port = $available_port;
    }

    $oct_obj = new octave();

    if(!$oct_obj->open_octave()){
        return false;
    }   

    $this->server_log('OCTAVE PROCESS STARTED');

    $cmd_id = 0;

    $server_socket_address = 'tcp://127.0.0.1:' . $this->port;

    $socket = stream_socket_server($server_socket_address, $errno, $errstr);
    if (!$socket) {
      $this->errstr = "$errstr ($errno)<br />\n";
      $this->errno = $errno;
      $oct_obj->close_octave();
      $this->server_log("<b>LISTENING SOCKET CREATION ERROR: $this->errstr</b>");
      return false;
    } 

    $exit = false;

    $this->server_log("LISTENING SOCKET CREATED: $server_socket_address    DEFAULT SOCKET TIMEOUT:" .  ini_get("default_socket_timeout"));
    $this->server_log($server_socket_address,'server_ready'); // dedicated event type sent, html page has a dedicated event listener on it

    $accept_retray = -1; 
    $conn_id = 0;  

    do{
        $accept_retray += 1;
        while ($conn = stream_socket_accept($socket)) {
            $this->server_log("LISTENING SOCKET CONNECTION ACCEPTED: $conn_id");

            $accept_retray = -1;

            //cmd: received octave command request to be sent to octave
            $cmd = '';

            $cmd = fread($conn,8192); 

            if($cmd === false){
                $this->server_log( __FUNCTION__ . "[$conn_id] fread ERROR for CMD: " . htmlentities($cmd));
                return false;
            }   
            $this->server_log("[$conn_id] RECEIVED RAW COMMAND: $cmd");


            if(strpos($cmd, '@exit@') !== false){
                //special command EXIT
                $this->server_log("[$conn_id] RECEIVED EXIT COMMAND.");
                fwrite($conn,self::prefix($conn_id) . 'RECEIVED EXIT COMMAND.'); // you need always to send an answer to the calling (it is waiting on read it
                $exit = true;
            }else if (strpos($cmd, '@loopback:') !== false) {
                //special command LOOPBACK
                $this->server_log("[$conn_id] RECEIVED LOOPBACK COMMAND: $cmd");
                fwrite($conn,self::prefix($conn_id) . $cmd); // you need always to send an answer to the calling (it is waiting on read it
            } else {    
                //OCATVE COMMAND
                $this->server_log("[$conn_id] RECEIVED COMMAND FOR OCTAVE: $cmd");
                $cmd_id = 0;
                $ret = $oct_obj->octave_cmd($cmd,$cmd_id);
                $this->server_log("[$conn_id] COMMAND # $cmd_id: " .htmlentities($cmd) . (($ret != '')?(' RESULT: ' . nl2br(htmlentities($ret))):'') . ' END<br>');
                fwrite($conn,self::prefix($conn_id) . 'RESULT:'. $ret);
                $this->server_log("[$conn_id] SENT ANSWER: RESULT:". $ret);

            }   

            fclose($conn);
            $this->server_log("[$conn_id] CLOSE CONNECTION");
            $conn_id++;

            if($exit) break;
        }

        if($exit) break;

        //note, calling the server_log func here you are testing the socket between this script and the html pages. If the sse connection is no more working, the PHP engine will close this script.
        $this->server_log("LISTENING SOCKET CONNECTION TIMEOUT RETRAY: $accept_retray MAX_RETRAY: $accept_max_retray");

    }while($accept_retray < $accept_max_retray);

    $this->server_log($server_socket_address,'server_stopped'); // dedicated event type sent

    fclose($socket);
    $this->server_log('SOCKET CLOSED.');

    unset($oct_obj);
    $this->server_log('OCTAVE PROCESS STOPPED.');

    return true;

} // end start_server

private static function prefix($conn_id){
    return "[$conn_id] ["  . date('n/j/Y g:i:s a') .'] ';
}   


//return the ocatve command answer to be encoded e.g. json to be delivered to the http page or false
public function send_cmd($cmd){
    if($this->server_istance){
        $this->errstr = '<br>'. __FUNCTION__ . ' SERVER ISTANCE.';
        return false;
    }   

    $ret = '';
    $fp = stream_socket_client($this->address . ':' .$this->port , $errno, $errstr, 30);
    if ($fp === false) {
        $this->errstr = "$errstr ($errno)<br />\n";
        $this->errno = $errno;
        return false;
    } else {
        //fwrite($fp, "GET / HTTP/1.0\r\nHost: www.example.com\r\nAccept: */*\r\n\r\n");
        fwrite($fp, $cmd);
        while (!feof($fp)) {
            $ret .= fgets($fp, 1024);
        }
        fclose($fp);
    }
    return $ret;
} // end send_cmd   

//return false or the server answer
public function stop_server(){
    if($this->server_istance){
        $this->errstr = '<br>'. __FUNCTION__ . ' SERVER ISTANCE.';
        $this->errno = 0;
        return false;
    }   
    return $this->send_cmd('@exit@');

} //

//return false or the server answer
public function loopback_msg($msg){
    if($this->server_istance){
        $this->errstr = '<br>'. __FUNCTION__ . ' SERVER ISTANCE.';
        $this->errno = 0;
        return false;
    }   
    return $this->send_cmd('@loopback:' . $msg);
}

public function get_errstr(&$errno){
    $ret = $this->errstr;
    $this->errstr = '';

    $errno = $this->errno;
    $this->errno = 0;

    return $ret;
}   

//$ip_name: IP or dns name
public function set_address_connection($ip_name,$port){
    $this->address = 'tcp://' . $ip_name  ;
    $this->port = $port;
}   

//str can be encoded as json if you need to transfert more data field.
//see: https://www.html5rocks.com/en/tutorials/eventsource/basics/
private function server_log($str,$event_name = ''){
    $msg = '<br>[' . date('n/j/Y g:i:s a') .'] '. $str ;
    if($this->sse){
        if($event_name != ''){
            echo "event: $event_name" . PHP_EOL;
            echo "data: $str" . PHP_EOL;
        }else{  
            echo "data: $msg" . PHP_EOL;
        }   
        echo PHP_EOL;
    }else{
        echo $msg;
    }


    ob_flush();
    flush();
}   

public function set_sse($sse){
    $this->sse = $sse;
}   

private function check_server_running_on_port($port,&$ret_errstr,&$errno){
    if(!$this->server_istance){
        $ret_errstr = '<br>'. __FUNCTION__ . ' REQUIRED SERVER ISTANCE.';
        $errno = 0;
        return false;
    }   

    $ret_errstr ='';
    $errno = 0;

    $msg = __FUNCTION__ . ' PORT CHECK: ' . $port;
    $cmd = '@loopback:' . $msg; // you cannot change it, is the defined loopback command

    $fp = stream_socket_client($this->address . ':' .$port , $errno, $errstr, 30);
    if ($fp === false) {
        $ret_errstr = "$errstr ($errno)<br />\n";
        return false;
    }

    fwrite($fp, $cmd);
    while (!feof($fp)) {
        $ret .= fgets($fp, 1024);
    }
    fclose($fp);

    return true;
}

private function find_usable_listening_port($start_port){
    if(!$this->server_istance){
        $this->errstr = '<br>'. __FUNCTION__ . ' REQUIRED SERVER ISTANCE.';
        $this->errno = 0;
        return false;
    }
    $ret_errstr ='';
    $errno = 0;

    $max_port = $start_port +10;

    $port = $start_port;
    do{
        //ret = true server running, so I need to find another unused port
        $ret = $this->check_server_running_on_port($port,$ret_errstr,$errno);
        if($ret){
            $this->server_log("CHECK USABLE LISTENING PORT: PORT=$port ALREADY USED.");
        }else{
            $this->server_log("CHECK USABLE LISTENING PORT: PORT=$port NOT USED. GIVEN ERROR: $ret_errstr" );
            return $port;
        }   
        $port++;

        if($port > $max_port) return false;
    }while($ret);

    return false;
}   

}   // end class 

?>

octave_sse.php

<?php
    /* this page should be called by the web page as sse 
       this page calling the create_server func start the octave process and the communication server as well.
       The function return only when the exit command is received over the server channel created.
       Then the page has to send a polling to the web page to test the presence of the page itself.
    */

    function sendMsg($sse,$msg) {
        if($sse){
            echo "data: $msg" . PHP_EOL;
            echo PHP_EOL;
        }else{
            echo $msg;
        }
        ob_flush();
        flush();
    }

    $sse = false;

    if(isset($_GET['sse'])){ 
        if($_GET['sse'] > 0){ 
            $sse = true;
        }
    }

    if($sse){
        header('Content-Type: text/event-stream');
    }else{
        header( 'Content-type: text/html; charset=utf-8' );
    }   

    header('Cache-Control: no-cache'); // recommended to prevent caching of event data.

    require 'octave.php';
    set_time_limit(4000);



    $oct_server_obj = new octave_stream();
    if($sse){ 
        $oct_server_obj->set_sse(true);

    }

    sendMsg($sse,'<br>[' . date('n/j/Y g:i:s a') .'] CALLING create_server.<br>');

    $ret = $oct_server_obj->create_server();

    sendMsg($sse,'<br>[' . date('n/j/Y g:i:s a') .'] create_server EXIT. return: '. (($ret)?'TRUE':'FALSE').'<br>');


    //you are here only at the end when the web page send the exit command to the created server

    do{
        sleep(2);
        sendMsg($sse,'<br>[' . date('n/j/Y g:i:s a') .'] create_server PING<br>');
    }while(true);

?>

octave_com.php

<?php
    /*
    This page is called using a json post request from web page.
    Each request has a octave command. special param is to terminate the server.
    */


    /** Error reporting: this is not used since you are using myErrorHandler */
    if($_SERVER['SERVER_NAME'] == "localhost"){ // my PC
       error_reporting(E_ALL);
    }else{
       error_reporting(E_ERROR | E_PARSE);
    }

    //http://php.net/manual/it/errorfunc.configuration.php#ini.display-errors
    /* The errors are redirect over the stderr and not over the stdout.
        In this way, you have to properly send the error using json without using the set_error_handler. 
        ini_set('display_errors','Off'); 
        //ini_set('display_errors','On'); 
    */

    function myErrorHandler ($errno, $errstr, $errfile, $errline) {
        if (0 === error_reporting()) { return false;}

        $errorType = array (
               E_ERROR            => 'ERROR',
               E_WARNING        => 'WARNING',
               E_PARSE          => 'PARSING ERROR',
               E_NOTICE         => 'NOTICE',
               E_CORE_ERROR     => 'CORE ERROR',
               E_CORE_WARNING   => 'CORE WARNING',
               E_COMPILE_ERROR  => 'COMPILE ERROR',
               E_COMPILE_WARNING => 'COMPILE WARNING',
               E_USER_ERROR     => 'USER ERROR',
               E_USER_WARNING   => 'USER WARNING',
               E_USER_NOTICE    => 'USER NOTICE',
               E_STRICT         => 'STRICT NOTICE',
               E_RECOVERABLE_ERROR  => 'RECOVERABLE ERROR');

        // create error message
        if (array_key_exists($errno, $errorType)) {
            $err = $errorType[$errno];
        } else {
            $err = 'CAUGHT EXCEPTION';
        }

        if($_SERVER['SERVER_NAME'] != "localhost"){ // not my PC
            if (!($errorType == E_ERROR ) || ($errorType == E_PARSE ))
                return;
        }

        $str_err = "$err($errno) <br>  in line: " .$errline. " of file: " .$errfile . " <br> PHP: " . PHP_VERSION . " (". PHP_OS .")<br> $errstr";

        terminate($str_err);        

    } // end myErrorHandler

    // configura il gestore dell'errore definito dall'utente
    $old_error_handler = set_error_handler("myErrorHandler");


    // functions

    function terminate($str_err, $txt=false){

     if($txt){
       die($str_err);
     }

     header("Content-Type: application/json;charset=utf-8");
     echo json_encode(array("result"=>"false","error"=>$str_err)); 
     exit(0);

    } // end terminate

    require 'octave.php';

    if(isset($_POST['send_loopback'])){ 

        if(!isset($_POST['message'])){
              terminate("message not present!");
           }else{
              $message =  $_POST['message'];
           }

        $address = '';
        $ip='';
        $port = 0;
        if(isset($_POST['address'])){
            $address =  $_POST['address'];
             $pos = strrpos($address,':');
             $ip = substr($address,6,$pos-6);
             $port = substr($address,$pos+1);
        }

        $oct_server_obj = new octave_stream();

        //it is supposed to have the server already running ready to manage the sent messages here below

        //echo '<br>[' . date('n/j/Y g:i:s a') .'] SEND THE LOOPBACK MESSAGE.<br>';

        if($ip != '' and is_numeric($port)){
            $oct_server_obj->set_address_connection($ip,$port);
        }

        $msg = $oct_server_obj->loopback_msg($message);

        if($msg === false){
            $errno = 0;
            terminate($oct_server_obj->get_errstr($errno));
        }

        echo json_encode(array('result' => 'true', 'error' => '', 'loopback_msg' => $msg)) ;
        exit(0);

    } // end send_loopback

    if(isset($_POST['send_octave_msg'])){ 

        if(!isset($_POST['message'])){
              terminate("message not present!");
           }else{
              $message =  $_POST['message'];
           }

         $address = '';
         $ip='';
         $port = 0;
         if(isset($_POST['address'])){
            $address =  $_POST['address'];
             $pos = strrpos($address,':');
             $ip = substr($address,6,$pos-6);
             $port = substr($address,$pos+1);
         }

        $oct_server_obj = new octave_stream();

        //it is supposed to have the server already running ready to manage the sent messages here below

        //echo '<br>[' . date('n/j/Y g:i:s a') .'] SEND THE LOOPBACK MESSAGE.<br>';

        if($ip != '' and is_numeric($port)){
            $oct_server_obj->set_address_connection($ip,$port);
        }   

        $msg = $oct_server_obj->send_cmd($message);

        if($msg === false){
            $errno = 0;
            terminate($oct_server_obj->get_errstr($errno));
        }

        $pos = strpos($msg,'RESULT:');
        $ret = trim(substr($msg,$pos+strlen('RESULT:')));

        $ret = nl2br(htmlentities($ret));

        echo json_encode(array('result' => 'true', 'error' => '', 'msg' => $msg, 'return' => $ret)) ;
        exit(0);

    } // end send_octave_msg

    if(isset($_GET['send_exit_msg'])){ 

        $address = '';
        $ip='';
        $port = 0;
        if(isset($_GET['address'])){
            $address =  $_GET['address'];
             $pos = strrpos($address,':');
             $ip = substr($address,6,$pos-6);
             $port = substr($address,$pos+1);
        }

        $oct_server_obj = new octave_stream();

        //it is supposed to have the server already running ready to manage the sent messages here below

        //echo '<br>[' . date('n/j/Y g:i:s a') .'] SEND THE LOOPBACK MESSAGE.<br>' . "ADDRESS: $address IP: $ip PORT: $port<br>" ;

        if($ip != '' and is_numeric($port)){
            $oct_server_obj->set_address_connection($ip,$port);
        }

        $msg = $oct_server_obj->stop_server();

        if($msg === false){
            $errno = 0;
            terminate($oct_server_obj->get_errstr($errno));
        }

        echo json_encode(array('result' => 'true', 'error' => '', 'return' => $msg)) ;
        exit(0);

    } // end send_exit_msg

?>

答案 1 :(得分:0)

与上面的代码一起使用的html网页。

octave_shell.html:

<!doctype html>
<html lang="en">
  <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

        <link rel="stylesheet" href="../../jquery/jqueryui/jquery-ui-1.11.3.custom/jquery-ui.css"> 
        <link rel="stylesheet" href="../../libs/messi/messi.min.css" />

        <script type="text/javascript" src="https://code.jquery.com/jquery-1.11.0.min.js"></script>

        <script src="../../jquery/jqueryui/jquery-ui-1.11.3.custom/jquery-ui.js"></script>

        <script src="../../libs/messi/my_messi.min.js"></script>
        <script src="../../libs/chosen/chosen.jquery.min.js"></script>

        <title>OCTAVE SHELL</title>
  </head>
  <body>
    <h2>OCTAVE WEB INTERFACE</h2>
     <script type="text/javascript">

        var server_ready = false; // true, octave process running and ready to accept commands
        var sse_source; // sse_obj

        var octave_close_req = false; // true when the user stop octave

        var address = ''; //address on which the server is in listening for commands at server side


        function clearArray(array_tbc){
            array_tbc.splice(0,array_tbc.length); // set the array to empty
            array_tbc.length = 0;
        }

        function isParamExist(paramName){
            if($.inArray(paramName,Object.getOwnPropertyNames(urlParams)) > -1){ 
              console.log("isParamExist:" + paramName + " return TRUE");
              return true;
            }
            console.log("isParamExist:" + paramName + " return FALSE");
            return false;   
        } //end isParamExist

        function getParam(urlParams) {
            var match,
                pl     = /\+/g,  // Regex for replacing addition symbol with a space
                search = /([^&=]+)=?([^&]*)/g,
                decode = function (s) { return decodeURIComponent(s.replace(pl, " ")); },
                query  = window.location.search.substring(1);

            while (match = search.exec(query))
               urlParams[decode(match[1])] = decode(match[2]);

            console.log(Object.getOwnPropertyNames(urlParams));
        } //end getParam

        function octave_close(){
            octave_close_req = true;

            $.getJSON('octave_com.php',

            {send_exit_msg: 1,
             address: address}, 

             function(data) {
                   if(data.result == "true"){
                        $('#octave_shell').append("<p><b>"+ data.return +"</b></p>" );
                   }else{   
                        //alert("Error : "   + data.error);  
                        new Messi('Error : '   + data.error, {title: 'ERROR from JSON', titleClass: 'anim error', buttons: [{id: 0, label: 'Close', val: 'X'}]});

                   }
               } 
             );
        } //end octave_close

        function ping_server(){
            var message = 'HELLO!';
            $.post( "octave_com.php", 
                { send_loopback: 1,
                  address: address,
                  message: message  } ,  
                 function( data ) {
                    if(data.result == 'true'){
                         var msg = data.loopback_msg;

                          $('#octave_shell').append("<p><b>"+ msg +"</b></p>" );

                    }else{
                        var err = data.error;
                        new Messi("LOOPBACK ERROR:  err: "  + err, {title: 'LOOPBACK MESSAGE', titleClass: 'anim warning', buttons: [{id: 0, label: 'Close', val: 'X'}]});
                    }

                }, 
                "json");
        } //end ping_server

        function send_octave_cmd(cmd){

            $.post( "octave_com.php", 
                { send_octave_msg: 1,
                  address: address,
                  message: cmd  } ,  
                 function( data ) {
                    if(data.result == 'true'){
                         var msg = data.return;

                          if(msg == '') msg = 'OK';
                          $('#octave_shell').append("<p>OCTAVE ANSWER: " + msg + "</p>");
                          console.log('OCTAVE MESSAGE: ' + data.msg);

                    }else{
                        var err = data.error;
                        new Messi("OCTAVE COMMAND:  err: "  + err, {title: 'OCTAVE COMMAND ERROR', titleClass: 'anim warning', buttons: [{id: 0, label: 'Close', val: 'X'}]});
                    }

                }, 
                "json");
        } //end send_octave_cmd

        $(function(){
                if(typeof(EventSource) !== "undefined") {
                    sse_source = new EventSource("octave_sse.php?sse=1");
                    sse_source.onmessage = function(event) {
                        console.log('SSE MSG: ' + event.data);
                        document.getElementById("sse_log").innerHTML += event.data + "<br>";
                    }; 

                    sse_source.addEventListener('open', function(e) {
                      // Connection was opened.
                        console.log('SSE OPEN.');
                        document.getElementById("sse_log").innerHTML += 'SSE OPEN.' + "<br>";
                    }, false);

                    sse_source.addEventListener('error', function(e) {
                      if (e.readyState == EventSource.CLOSED) {
                        // Connection was closed.
                        server_ready = false;
                        console.log('SSE CLOSED.');
                        document.getElementById("sse_log").innerHTML += 'SSE CLOSED.' + "<br>";
                      }
                    }, false);

                    //user defined event types
                    sse_source.addEventListener('server_ready', function(e) {
                        // server_ready event received.
                        server_ready = true;
                        address =  e.data;
                        console.log('SSE server_ready EVENT ADDR: ' + address);
                        $('#octave_status').text('SERVER READY TO ACCEPT OCTAVE COMMANDS ON: '+ address);
                    }, false);

                    sse_source.addEventListener('server_stopped', function(e) {
                        // server_stopped event received.
                        server_ready = false;
                        console.log('SSE server_stopped EVENT');

                        setTimeout(function(){ sse_source.close(); }, 3000); //close the sse connection as well, you don't need anymore.
                        if(!octave_close_req){
                            $('#octave_status').text('SERVER HAS BEEN CLOSED FOR TIMEOUT. RE-LOAD THE PAGE TO START A NEW WORKING SESSION.');
                            new Messi(
                                'OCTAVE PROCESS STOPPED FOR TIMEOUT. RE-LOAD THE PAGE TO START A NEW WORKING SESSION.',
                                {
                                    title: 'OCTAVE PROCESS STOPPED',
                                    titleClass: 'anim info',
                                    buttons: [ {id: 0, label: 'Close', val: 'X'} ]
                                }
                            );
                        }else{
                            $('#octave_status').text('SERVER HAS BEEN CLOSED FOR USER DECISION. RE-LOAD THE PAGE TO START A NEW WORKING SESSION.');
                            new Messi(
                                'YOU HAVE CLOSED CORRECTLY THE OCTAVE PROCESS. RE-LOAD THE PAGE TO START A NEW WORKING SESSION.',
                                {
                                    title: 'OCTAVE PROCESS STOPPED',
                                    titleClass: 'anim info',
                                    buttons: [ {id: 0, label: 'Close', val: 'X'} ]
                                }
                            );
                        }
                    }, false);

                } else {
                    alert('NO SSE SUPPORT. Please do not use an obsolete browser!');
                } 

                $('#close_octave_id').click(function() {
                      console.log('CLOSE OCTAVE REQUEST');
                      octave_close();
                    });


                $('#send_ping_id').click(function() {
                      console.log('PING DISPATCHER SERVER REQUEST');
                      ping_server();
                    });

                $('#send_octave_cmd_id').click(function() {
                      var cmd = $('#write_octave_cmd_id').val();
                      //console.log('SEND OCTAVE CMD REQUEST: ' + cmd);
                      $('#octave_shell').append("<p>OCTAVE: " + cmd + "</p>");
                      send_octave_cmd(cmd);
                      $('#write_octave_cmd_id').val('');
                    });

                $('#write_octave_cmd_id').keypress(function (e) {
                     var key = e.which;
                     if(key == 13)  // the enter key code
                      {
                        $('#send_octave_cmd_id').click();
                        return false;  
                      }
                    });   

              //getParam(urlParams);
              /*
              if(!isParamExist('json_file_net_name')){
                //load the NPT results
                loadNPTData();  
              }else{
                // load DESIGN results
                loadJSONData(); 
              }
              */

          }); // end startup page
     </script>

     <div id='octave_cmd'>
        <h4>Write your OCTAVE commands here, press enter or click on SEND OCTAVE CMD to execute them.<br>
            <b>IMPORTANT: </b>Don't forget to terminate the commands with semicolon as per OCTAVE syntax.</h4>
        <br><p>Some example commands: disp(10) just to print 10,<br>
                to solve a non linear system equation writes the following commands line by line pressing enter for each row:<br>
                <i>function y = test6(x)<br>
                y(1) = 18.028*cosd(x(1))+10*cosd(45)-15*cosd(x(2))<br>
                y(2) = 18.028*sind(x(1))+10*sind(45)-15*sind(x(2))<br>
                endfunction<br>
                [x, fval, info] = fsolve(@test6, [0;0]);<br>
                disp(x);<br>
                disp(info);</i><br>
        </p><br>        
     </div><br>
     <br><a href='#' id='close_octave_id' >CLOSE OCTAVE -  CLICK WHEN YOU HAVE TERMINATED.</a><br>
     <br><a href='#' id='send_ping_id' >PING DISPATCHER SERVER </a><br>
     <div id='octave_status'></div>
     <br><div id='octave_shell'><h4>OCTAVE SHELL:</h4><br></div><br>
     <input type='text' id='write_octave_cmd_id'  size="400"><br>
     <a href='#' id='send_octave_cmd_id' >SEND OCTAVE CMD</a>
     <br><div id='sse_log'><h4>SSE LOG:</h4><br></div><br>
  </body>
</html>