phpagi.php

<?php
//	License for all code of this IssabelPBX module can be found in the license file inside the module directory
//	Copyright 2013 Schmooze Com Inc.
//  Copyright (c) 2003, 2004, 2005 Matthew Asham <matthewa@bcwireless.net>, David Eder <david@eder.us>
//

 /**
  */

  if(!class_exists('AGI_AsteriskManager')) {
    require_once(dirname(__FILE__) . DIRECTORY_SEPARATOR . 'phpagi-asmanager.php');
  }

  define('AST_CONFIG_DIR', '/etc/asterisk/');
  define('AST_SPOOL_DIR', '/var/spool/asterisk/');
  define('AST_TMP_DIR', AST_SPOOL_DIR . '/tmp/');
  define('DEFAULT_PHPAGI_CONFIG', AST_CONFIG_DIR . '/phpagi.conf');

  define('AST_DIGIT_ANY', '0123456789#*');

  define('AGIRES_OK', 200);

  define('AST_STATE_DOWN', 0);
  define('AST_STATE_RESERVED', 1);
  define('AST_STATE_OFFHOOK', 2);
  define('AST_STATE_DIALING', 3);
  define('AST_STATE_RING', 4);
  define('AST_STATE_RINGING', 5);
  define('AST_STATE_UP', 6);
  define('AST_STATE_BUSY', 7);
  define('AST_STATE_DIALING_OFFHOOK', 8);
  define('AST_STATE_PRERING', 9);

  define('AUDIO_FILENO', 3); // STDERR_FILENO + 1

 /**
  * AGI class
  *
  * @package phpAGI
  * @link http://www.voip-info.org/wiki-Asterisk+agi
  * @example examples/dtmf.php Get DTMF tones from the user and say the digits
  * @example examples/input.php Get text input from the user and say it back
  * @example examples/ping.php Ping an IP address
  */
  class AGI
  {
   /**
    * Request variables read in on initialization.
    *
    * Often contains any/all of the following:
    *   agi_request - name of agi script
    *   agi_channel - current channel
    *   agi_language - current language
    *   agi_type - channel type (SIP, ZAP, IAX, ...)
    *   agi_uniqueid - unique id based on unix time
    *   agi_callerid - callerID string
    *   agi_dnid - dialed number id
    *   agi_rdnis - referring DNIS number
    *   agi_context - current context
    *   agi_extension - extension dialed
    *   agi_priority - current priority
    *   agi_enhanced - value is 1.0 if started as an EAGI script
    *   agi_accountcode - set by SetAccount in the dialplan
    *   agi_network - value is yes if this is a fastagi
    *   agi_network_script - name of the script to execute
    *
    * NOTE: program arguments are still in $_SERVER['argv'].
    *
    * @var array
    * @access public
    */
    var $request;

   /**
    * Config variables
    *
    * @var array
    * @access public
    */
    var $config;

   /**
    * Asterisk Manager
    *
    * @var AGI_AsteriskManager
    * @access public
    */
    var $asmanager;

   /**
    * Input Stream
    *
    * @access private
    */
    var $in = NULL;

   /**
    * Output Stream
    *
    * @access private
    */
    var $out = NULL;

   /**
    * FastAGI socket
    *
    * @access private
    */
    var $socket = NULL;

   /**
    * Audio Stream
    *
    * @access public
    */
    var $audio = NULL;

   /**
    * Constructor
    *
    * @param string $config is the name of the config file to parse
    * @param array $optconfig is an array of configuration vars and vals, stuffed into $this->config['phpagi']
    */
    function AGI($config=NULL, $optconfig=array(), $socket=NULL) {
      // load config
      if(!is_null($config) && file_exists($config))
        $this->config = parse_ini_file($config, true);
      elseif(file_exists(DEFAULT_PHPAGI_CONFIG))
        $this->config = parse_ini_file(DEFAULT_PHPAGI_CONFIG, true);

      // If optconfig is specified, stuff vals and vars into 'phpagi' config array.
      foreach($optconfig as $var=>$val)
        $this->config['phpagi'][$var] = $val;

      // add default values to config for uninitialized values
      if(!isset($this->config['phpagi']['error_handler'])) $this->config['phpagi']['error_handler'] = true;
      if(!isset($this->config['phpagi']['debug'])) $this->config['phpagi']['debug'] = false;
      if(!isset($this->config['phpagi']['admin'])) $this->config['phpagi']['admin'] = NULL;
      if(!isset($this->config['phpagi']['tempdir'])) $this->config['phpagi']['tempdir'] = AST_TMP_DIR;

      ob_implicit_flush(true);

      // open input & output
      if(is_null($socket))
      {
        $this->in  = defined('STDIN')  ? STDIN  : fopen('php://stdin',  'r');
        $this->out = defined('STDOUT') ? STDOUT : fopen('php://stdout', 'w');
      }
      else
        $this->socket = $socket;

      // initialize error handler
      if($this->config['phpagi']['error_handler'] == true)
      {
        set_error_handler('phpagi_error_handler');
        global $phpagi_error_handler_email;
        $phpagi_error_handler_email = $this->config['phpagi']['admin'];
//        error_reporting(E_ALL);
      }

      // make sure temp folder exists
      $this->make_folder($this->config['phpagi']['tempdir']);

      // read the request
      $str = is_null($this->socket) ? fgets($this->in) : socket_read($this->socket, 4096, PHP_NORMAL_READ);
      while($str != "\n")
      {
        $this->request[substr($str, 0, strpos($str, ':'))] = trim(substr($str, strpos($str, ':') + 1));
        $str = is_null($this->socket) ? fgets($this->in) : socket_read($this->socket, 4096, PHP_NORMAL_READ);
      }

      // open audio if eagi detected
      if($this->request['agi_enhanced'] == '1.0')
      {
        if(file_exists('/proc/' . getmypid() . '/fd/3'))
        {
          // this should work on linux
          $this->audio = fopen('/proc/' . getmypid() . '/fd/3', 'r');
        }
        elseif(file_exists('/dev/fd/3'))
        {
          // this should work on BSD. may need to mount fdescfs if this fails
          $this->audio = fopen('/dev/fd/3', 'r');
        }
        else
          $this->conlog('Unable to open audio stream');

        if($this->audio) stream_set_blocking($this->audio, 0);
      }

// Next two lines where removed 2009-08-25 due to unneccesary output when setting "core set verbose 3" or higher in Asterisk.
//
//    $this->conlog('PHPAGI internal configuration:');
//    $this->conlog(print_r($this->config, true));

// Enable for debuggin purposes
//foreach(explode("\n", print_r($this, true)) as $line) syslog(LOG_WARNING, $line);
    }

   // *********************************************************************************************************
   // **                       COMMANDS                                                                      **
   // *********************************************************************************************************

   /**
    * Answer channel if not already in answer state.
    *
    * @link http://www.voip-info.org/wiki-answer
    * @example examples/dtmf.php Get DTMF tones from the user and say the digits
    * @example examples/input.php Get text input from the user and say it back
    * @example examples/ping.php Ping an IP address
    *
    * @return array, see evaluate for return information.  ['result'] is 0 on success, -1 on failure.
    */
    function answer()
    {
      return $this->evaluate('ANSWER');
    }

   /**
    * Get the status of the specified channel. If no channel name is specified, return the status of the current channel.
    *
    * @link http://www.voip-info.org/wiki-channel+status
    * @param string $channel
    * @return array, see evaluate for return information. ['data'] contains description.
    */
    function channel_status($channel='')
    {
      $ret = $this->evaluate("CHANNEL STATUS $channel");
      switch($ret['result'])
      {
        case -1: $ret['data'] = trim("There is no channel that matches $channel"); break;
        case AST_STATE_DOWN: $ret['data'] = 'Channel is down and available'; break;
        case AST_STATE_RESERVED: $ret['data'] = 'Channel is down, but reserved'; break;
        case AST_STATE_OFFHOOK: $ret['data'] = 'Channel is off hook'; break;
        case AST_STATE_DIALING: $ret['data'] = 'Digits (or equivalent) have been dialed'; break;
        case AST_STATE_RING: $ret['data'] = 'Line is ringing'; break;
        case AST_STATE_RINGING: $ret['data'] = 'Remote end is ringing'; break;
        case AST_STATE_UP: $ret['data'] = 'Line is up'; break;
        case AST_STATE_BUSY: $ret['data'] = 'Line is busy'; break;
        case AST_STATE_DIALING_OFFHOOK: $ret['data'] = 'Digits (or equivalent) have been dialed while offhook'; break;
        case AST_STATE_PRERING: $ret['data'] = 'Channel has detected an incoming call and is waiting for ring'; break;
        default: $ret['data'] = "Unknown ({$ret['result']})"; break;
      }
      return $ret;
    }

   /**
    * Deletes an entry in the Asterisk database for a given family and key.
    *
    * @link http://www.voip-info.org/wiki-database+del
    * @param string $family
    * @param string $key
    * @return array, see evaluate for return information. ['result'] is 1 on sucess, 0 otherwise.
    */
    function database_del($family, $key)
    {
      return $this->evaluate("DATABASE DEL \"$family\" \"$key\"");
    }

   /**
    * Deletes a family or specific keytree within a family in the Asterisk database.
    *
    * @link http://www.voip-info.org/wiki-database+deltree
    * @param string $family
    * @param string $keytree
    * @return array, see evaluate for return information. ['result'] is 1 on sucess, 0 otherwise.
    */
    function database_deltree($family, $keytree='')
    {
      $cmd = "DATABASE DELTREE \"$family\"";
      if($keytree != '') $cmd .= " \"$keytree\"";
      return $this->evaluate($cmd);
    }

   /**
    * Retrieves an entry in the Asterisk database for a given family and key.
    *
    * @link http://www.voip-info.org/wiki-database+get
    * @param string $family
    * @param string $key
    * @return array, see evaluate for return information. ['result'] is 1 on sucess, 0 failure. ['data'] holds the value
    */
    function database_get($family, $key)
    {
      return $this->evaluate("DATABASE GET \"$family\" \"$key\"");
    }

   /**
    * Adds or updates an entry in the Asterisk database for a given family, key, and value.
    *
    * @param string $family
    * @param string $key
    * @param string $value
    * @return array, see evaluate for return information. ['result'] is 1 on sucess, 0 otherwise
    */
    function database_put($family, $key, $value)
    {
      $value = str_replace("\n", '\n', addslashes($value));
      return $this->evaluate("DATABASE PUT \"$family\" \"$key\" \"$value\"");
    }

   /**
    * Executes the specified Asterisk application with given options.
    *
    * @link http://www.voip-info.org/wiki-exec
    * @link http://www.voip-info.org/wiki-Asterisk+-+documentation+of+application+commands
    * @param string $application
    * @param mixed $options
    * @return array, see evaluate for return information. ['result'] is whatever the application returns, or -2 on failure to find application
    */
    function exec($application, $options)
    {
      if(is_array($options)) $options = join(',', $options);
      return $this->evaluate("EXEC $application $options");
    }

   /**
    * Plays the given file and receives DTMF data.
    *
    * This is similar to STREAM FILE, but this command can accept and return many DTMF digits,
    * while STREAM FILE returns immediately after the first DTMF digit is detected.
    *
    * Asterisk looks for the file to play in /var/lib/asterisk/sounds by default.
    *
    * If the user doesn't press any keys when the message plays, there is $timeout milliseconds
    * of silence then the command ends. 
    *
    * The user has the opportunity to press a key at any time during the message or the
    * post-message silence. If the user presses a key while the message is playing, the
    * message stops playing. When the first key is pressed a timer starts counting for
    * $timeout milliseconds. Every time the user presses another key the timer is restarted.
    * The command ends when the counter goes to zero or the maximum number of digits is entered,
    * whichever happens first. 
    *
    * If you don't specify a time out then a default timeout of 2000 is used following a pressed
    * digit. If no digits are pressed then 6 seconds of silence follow the message. 
    *
    * If you don't specify $max_digits then the user can enter as many digits as they want. 
    *
    * Pressing the # key has the same effect as the timer running out: the command ends and
    * any previously keyed digits are returned. A side effect of this is that there is no
    * way to read a # key using this command.
    *
    * @example examples/ping.php Ping an IP address
    *
    * @link http://www.voip-info.org/wiki-get+data
    * @param string $filename file to play. Do not include file extension.
    * @param integer $timeout milliseconds
    * @param integer $max_digits
    * @return array, see evaluate for return information. ['result'] holds the digits and ['data'] holds the timeout if present.
    *
    * This differs from other commands with return DTMF as numbers representing ASCII characters.
    */
    function get_data($filename, $timeout=NULL, $max_digits=NULL)
    {
      return $this->evaluate(rtrim("GET DATA $filename $timeout $max_digits"));
    }

   /**
    * Fetch the value of a variable.
    *
    * Does not work with global variables. Does not work with some variables that are generated by modules.
    *
    * @link http://www.voip-info.org/wiki-get+variable
    * @link http://www.voip-info.org/wiki-Asterisk+variables
    * @param string $variable name
    * @return array, see evaluate for return information. ['result'] is 0 if variable hasn't been set, 1 if it has. ['data'] holds the value.
    */
    function get_variable($variable)
    {
      return $this->evaluate("GET VARIABLE $variable");
    }

   /**
    * Hangup the specified channel. If no channel name is given, hang up the current channel.
    *
    * With power comes responsibility. Hanging up channels other than your own isn't something
    * that is done routinely. If you are not sure why you are doing so, then don't.
    *
    * @link http://www.voip-info.org/wiki-hangup
    * @example examples/dtmf.php Get DTMF tones from the user and say the digits
    * @example examples/input.php Get text input from the user and say it back
    * @example examples/ping.php Ping an IP address
    *
    * @param string $channel
    * @return array, see evaluate for return information. ['result'] is 1 on success, -1 on failure.
    */
    function hangup($channel='')
    {
      return $this->evaluate("HANGUP $channel");
    }

   /**
    * Does nothing.
    *
    * @link http://www.voip-info.org/wiki-noop
    * @return array, see evaluate for return information.
    */
    function noop()
    {
      return $this->evaluate('NOOP');
    }

   /**
    * Receive a character of text from a connected channel. Waits up to $timeout milliseconds for
    * a character to arrive, or infinitely if $timeout is zero.
    *
    * @link http://www.voip-info.org/wiki-receive+char
    * @param integer $timeout milliseconds
    * @return array, see evaluate for return information. ['result'] is 0 on timeout or not supported, -1 on failure. Otherwise 
    * it is the decimal value of the DTMF tone. Use chr() to convert to ASCII.
    */
    function receive_char($timeout=-1)
    {
      return $this->evaluate("RECEIVE CHAR $timeout");
    }

   /**
    * Record sound to a file until an acceptable DTMF digit is received or a specified amount of
    * time has passed. Optionally the file BEEP is played before recording begins.
    *
    * @link http://www.voip-info.org/wiki-record+file
    * @param string $file to record, without extension, often created in /var/lib/asterisk/sounds
    * @param string $format of the file. GSM and WAV are commonly used formats. MP3 is read-only and thus cannot be used.
    * @param string $escape_digits
    * @param integer $timeout is the maximum record time in milliseconds, or -1 for no timeout.
    * @param integer $offset to seek to without exceeding the end of the file.
    * @param boolean $beep
    * @param integer $silence number of seconds of silence allowed before the function returns despite the 
    * lack of dtmf digits or reaching timeout.
    * @return array, see evaluate for return information. ['result'] is -1 on error, 0 on hangup, otherwise a decimal value of the 
    * DTMF tone. Use chr() to convert to ASCII.
    */
    function record_file($file, $format, $escape_digits='', $timeout=-1, $offset=NULL, $beep=false, $silence=NULL)
    {
      $cmd = trim("RECORD FILE $file $format \"$escape_digits\" $timeout $offset");
      if($beep) $cmd .= ' BEEP';
      if(!is_null($silence)) $cmd .= " s=$silence";
      return $this->evaluate($cmd);
    }

   /**
    * Say the given digit string, returning early if any of the given DTMF escape digits are received on the channel.
    *
    * @link http://www.voip-info.org/wiki-say+digits
    * @param integer $digits
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no 
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function say_digits($digits, $escape_digits='')
    {
      return $this->evaluate("SAY DIGITS $digits \"$escape_digits\"");
    }

   /**
    * Say the given number, returning early if any of the given DTMF escape digits are received on the channel.
    *
    * @link http://www.voip-info.org/wiki-say+number
    * @param integer $number
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no 
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function say_number($number, $escape_digits='')
    {
      return $this->evaluate("SAY NUMBER $number \"$escape_digits\"");
    }

   /**
    * Say the given character string, returning early if any of the given DTMF escape digits are received on the channel.
    *
    * @link http://www.voip-info.org/wiki-say+phonetic
    * @param string $text
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no 
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function say_phonetic($text, $escape_digits='')
    {
      return $this->evaluate("SAY PHONETIC $text \"$escape_digits\"");
    }

   /**
    * Say a given time, returning early if any of the given DTMF escape digits are received on the channel.
    *
    * @link http://www.voip-info.org/wiki-say+time
    * @param integer $time number of seconds elapsed since 00:00:00 on January 1, 1970, Coordinated Universal Time (UTC).
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no 
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function say_time($time=NULL, $escape_digits='')
    {
      if(is_null($time)) $time = time();
      return $this->evaluate("SAY TIME $time \"$escape_digits\"");
    }

   /**
    * Send the specified image on a channel.
    *
    * Most channels do not support the transmission of images.
    *
    * @link http://www.voip-info.org/wiki-send+image
    * @param string $image without extension, often in /var/lib/asterisk/images
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if the image is sent or 
    * channel does not support image transmission.
    */
    function send_image($image)
    {
      return $this->evaluate("SEND IMAGE $image");
    }

   /**
    * Send the given text to the connected channel.
    *
    * Most channels do not support transmission of text.
    *
    * @link http://www.voip-info.org/wiki-send+text
    * @param $text
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if the text is sent or 
    * channel does not support text transmission.
    */
    function send_text($text)
    {
      return $this->evaluate("SEND TEXT \"$text\"");
    }

   /**
    * Cause the channel to automatically hangup at $time seconds in the future.
    * If $time is 0 then the autohangup feature is disabled on this channel.
    *
    * If the channel is hungup prior to $time seconds, this setting has no effect.
    *
    * @link http://www.voip-info.org/wiki-set+autohangup
    * @param integer $time until automatic hangup
    * @return array, see evaluate for return information.
    */
    function set_autohangup($time=0)
    {
      return $this->evaluate("SET AUTOHANGUP $time");
    }

   /**
    * Changes the caller ID of the current channel.
    *
    * @link http://www.voip-info.org/wiki-set+callerid
    * @param string $cid example: "John Smith"<1234567>
    * This command will let you take liberties with the <caller ID specification> but the format shown in the example above works 
    * well: the name enclosed in double quotes followed immediately by the number inside angle brackets. If there is no name then
    * you can omit it. If the name contains no spaces you can omit the double quotes around it. The number must follow the name
    * immediately; don't put a space between them. The angle brackets around the number are necessary; if you omit them the
    * number will be considered to be part of the name.
    * @return array, see evaluate for return information.
    */
    function set_callerid($cid)
    {
      return $this->evaluate("SET CALLERID $cid");
    }

   /**
    * Sets the context for continuation upon exiting the application.
    *
    * Setting the context does NOT automatically reset the extension and the priority; if you want to start at the top of the new 
    * context you should set extension and priority yourself. 
    *
    * If you specify a non-existent context you receive no error indication (['result'] is still 0) but you do get a 
    * warning message on the Asterisk console.
    *
    * @link http://www.voip-info.org/wiki-set+context
    * @param string $context 
    * @return array, see evaluate for return information.
    */
    function set_context($context)
    {
      return $this->evaluate("SET CONTEXT $context");
    }

   /**
    * Set the extension to be used for continuation upon exiting the application.
    *
    * Setting the extension does NOT automatically reset the priority. If you want to start with the first priority of the 
    * extension you should set the priority yourself. 
    *
    * If you specify a non-existent extension you receive no error indication (['result'] is still 0) but you do 
    * get a warning message on the Asterisk console.
    *
    * @link http://www.voip-info.org/wiki-set+extension
    * @param string $extension
    * @return array, see evaluate for return information.
    */
    function set_extension($extension)
    {
      return $this->evaluate("SET EXTENSION $extension");
    }

   /**
    * Enable/Disable Music on hold generator.
    *
    * @link http://www.voip-info.org/wiki-set+music
    * @param boolean $enabled
    * @param string $class
    * @return array, see evaluate for return information.
    */
    function set_music($enabled=true, $class='')
    {
      $enabled = ($enabled) ? 'ON' : 'OFF';
      return $this->evaluate("SET MUSIC $enabled $class");
    }

   /**
    * Set the priority to be used for continuation upon exiting the application.
    *
    * If you specify a non-existent priority you receive no error indication (['result'] is still 0)
    * and no warning is issued on the Asterisk console.
    *
    * @link http://www.voip-info.org/wiki-set+priority
    * @param integer $priority
    * @return array, see evaluate for return information.
    */
    function set_priority($priority)
    {
      return $this->evaluate("SET PRIORITY $priority");
    }

   /**
    * Sets a variable to the specified value. The variables so created can later be used by later using ${<variablename>}
    * in the dialplan.
    *
    * These variables live in the channel Asterisk creates when you pickup a phone and as such they are both local and temporary. 
    * Variables created in one channel can not be accessed by another channel. When you hang up the phone, the channel is deleted 
    * and any variables in that channel are deleted as well.
    *
    * @link http://www.voip-info.org/wiki-set+variable
    * @param string $variable is case sensitive
    * @param string $value
    * @return array, see evaluate for return information.
    */
    function set_variable($variable, $value)
    {
      $value = str_replace("\n", '\n', addslashes($value));
      return $this->evaluate("SET VARIABLE $variable \"$value\"");
    }

   /**
    * Play the given audio file, allowing playback to be interrupted by a DTMF digit. This command is similar to the GET DATA 
    * command but this command returns after the first DTMF digit has been pressed while GET DATA can accumulated any number of 
    * digits before returning.
    *
    * @example examples/ping.php Ping an IP address
    *
    * @link http://www.voip-info.org/wiki-stream+file
    * @param string $filename without extension, often in /var/lib/asterisk/sounds
    * @param string $escape_digits
    * @param integer $offset
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no 
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function stream_file($filename, $escape_digits='', $offset=0)
    {
      return $this->evaluate("STREAM FILE $filename \"$escape_digits\" $offset");
    }

   /**
    * Enable or disable TDD transmission/reception on the current channel.
    *
    * @link http://www.voip-info.org/wiki-tdd+mode
    * @param string $setting can be on, off or mate
    * @return array, see evaluate for return information. ['result'] is 1 on sucess, 0 if the channel is not TDD capable.
    */
    function tdd_mode($setting)
    {
      return $this->evaluate("TDD MODE $setting");
    }

   /**
    * Sends $message to the Asterisk console via the 'verbose' message system.
    *
    * If the Asterisk verbosity level is $level or greater, send $message to the console.
    *
    * The Asterisk verbosity system works as follows. The Asterisk user gets to set the desired verbosity at startup time or later 
    * using the console 'set verbose' command. Messages are displayed on the console if their verbose level is less than or equal 
    * to desired verbosity set by the user. More important messages should have a low verbose level; less important messages 
    * should have a high verbose level.
    *
    * @link http://www.voip-info.org/wiki-verbose
    * @param string $message
    * @param integer $level from 1 to 4
    * @return array, see evaluate for return information.
    */
    function verbose($message, $level=1)
    {
      foreach(explode("\n", str_replace("\r\n", "\n", print_r($message, true))) as $msg)
      {
// Enable for extra logging.
//        @syslog(LOG_WARNING, $msg);
        $ret = $this->evaluate("VERBOSE \"$msg\" $level");
      }
      return $ret;
    }

   /**
    * Waits up to $timeout milliseconds for channel to receive a DTMF digit.
    *
    * @link http://www.voip-info.org/wiki-wait+for+digit
    * @param integer $timeout in millisecons. Use -1 for the timeout value if you want the call to wait indefinitely.
    * @return array, see evaluate for return information. ['result'] is 0 if wait completes with no 
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
    function wait_for_digit($timeout=-1)
    {
      return $this->evaluate("WAIT FOR DIGIT $timeout");
    }


   // *********************************************************************************************************
   // **                       APPLICATIONS                                                                  **
   // *********************************************************************************************************

   /**
    * Set absolute maximum time of call.
    *
    * Note that the timeout is set from the current time forward, not counting the number of seconds the call has already been up. 
    * Each time you call AbsoluteTimeout(), all previous absolute timeouts are cancelled. 
    * Will return the call to the T extension so that you can playback an explanatory note to the calling party (the called party 
    * will not hear that)
    *
    * @link http://www.voip-info.org/wiki-Asterisk+-+documentation+of+application+commands
    * @link http://www.dynx.net/ASTERISK/AGI/ccard/agi-ccard.agi
    * @param $seconds allowed, 0 disables timeout
    * @return array, see evaluate for return information.
    */
    function exec_absolutetimeout($seconds=0)
    {
      return $this->exec('AbsoluteTimeout', $seconds);
    }

   /**
    * Executes an AGI compliant application.
    *
    * @param string $command
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or if application requested hangup, or 0 on non-hangup exit.
    * @param string $args
    * @return array, see evaluate for return information.
    */
    function exec_agi($command, $args)
    {
      return $this->exec("AGI $command", $args);
    }

   /**
    * Set Account Code
    *
    * Set the channel account code for billing purposes.
    *
    * @param string $accountcode
    * @return array, see evaluate for return information.        
    */
    function exec_setaccountcode($accountcode)
    {
      return $this->exec('SetAccount', $accountcode);
    }

   /**
    * Set Language.
    *
    * @param string $language code
    * @return array, see evaluate for return information.
    */
    function exec_setlanguage($language='en')
    {
      return $this->exec('SetLanguage', $language);
    }

   /**
    * SIPAddHeader
    *
    * @param string $header SIP Header
    * @param string $value SIP Header Value
    * @return array, see evaluate for return information.
    */
    function exec_sipaddheader($header, $value)
    {
      return $this->exec('SIPAddHeader', '"'.$header.":".$value.'"');
    }

   /**
    * Alertinfo
    *
    * @param string $value SIP Alertinfo to set
    * @return array, see evaluate for return information.
    */
    function set_alertinfo($value)
    {
      return $this->exec_sipaddheader('Alert-Info',$value);
    }

   /**
    * Do ENUM Lookup.
    *
    * Note: to retrieve the result, use
    *   get_variable('ENUM');
    *
    * @param $exten
    * @return array, see evaluate for return information.
    */
    function exec_enumlookup($exten)
    {
      return $this->exec('EnumLookup', $exten);
    }

   /**
    * Dial.
    *
    * Dial takes input from ${VXML_URL} to send XML Url to Cisco 7960
    * Dial takes input from ${ALERT_INFO} to set ring cadence for Cisco phones
    * Dial returns ${CAUSECODE}: If the dial failed, this is the errormessage.
    * Dial returns ${DIALSTATUS}: Text code returning status of last dial attempt.
    *
    * @link http://www.voip-info.org/wiki-Asterisk+cmd+Dial
    * @param string $type
    * @param string $identifier
    * @param integer $timeout
    * @param string $options
    * @param string $url
    * @return array, see evaluate for return information.
    */
    function exec_dial($type, $identifier, $timeout=NULL, $options=NULL, $url=NULL)
    {
      return $this->exec('Dial', trim("$type/$identifier,$timeout,$options,$url", ','));
    }

   /**
    * Goto.
    *
    * This function takes three arguments: context,extension, and priority, but the leading arguments
    * are optional, not the trailing arguments.  Thuse goto($z) sets the priority to $z.
    *
    * @param string $a
    * @param string $b;
    * @param string $c;
    * @return array, see evaluate for return information.
    */
    function exec_goto($a, $b=NULL, $c=NULL)
    {
      return $this->exec('Goto', trim("$a,$b,$c", ','));
    }


   // *********************************************************************************************************
   // **                       FAST PASSING                                                                  **
   // *********************************************************************************************************

   /**
    * Say the given digit string, returning early if any of the given DTMF escape digits are received on the channel.
    * Return early if $buffer is adequate for request.
    *
    * @link http://www.voip-info.org/wiki-say+digits
    * @param string $buffer
    * @param integer $digits
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
   function fastpass_say_digits(&$buffer, $digits, $escape_digits='')
   {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
       if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
         $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
       $res = $this->say_digits($digits, $escape_digits);
       if($res['code'] == AGIRES_OK && $res['result'] > 0)
         $buffer .= chr($res['result']);
       return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}));
   }

   /**
    * Say the given number, returning early if any of the given DTMF escape digits are received on the channel.
    * Return early if $buffer is adequate for request.
    *
    * @link http://www.voip-info.org/wiki-say+number
    * @param string $buffer
    * @param integer $number
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
   function fastpass_say_number(&$buffer, $number, $escape_digits='')
   {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
       if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
         $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
       $res = $this->say_number($number, $escape_digits);
       if($res['code'] == AGIRES_OK && $res['result'] > 0)
         $buffer .= chr($res['result']);
       return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}));
   }

   /**
    * Say the given character string, returning early if any of the given DTMF escape digits are received on the channel.
    * Return early if $buffer is adequate for request.
    *
    * @link http://www.voip-info.org/wiki-say+phonetic
    * @param string $buffer
    * @param string $text
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
   function fastpass_say_phonetic(&$buffer, $text, $escape_digits='')
   {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
       if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
         $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
       $res = $this->say_phonetic($text, $escape_digits);
       if($res['code'] == AGIRES_OK && $res['result'] > 0)
         $buffer .= chr($res['result']);
       return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}));
   }

   /**
    * Say a given time, returning early if any of the given DTMF escape digits are received on the channel.
    * Return early if $buffer is adequate for request.
    *
    * @link http://www.voip-info.org/wiki-say+time
    * @param string $buffer
    * @param integer $time number of seconds elapsed since 00:00:00 on January 1, 1970, Coordinated Universal Time (UTC).
    * @param string $escape_digits
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
   function fastpass_say_time(&$buffer, $time=NULL, $escape_digits='')
   {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
       if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
         $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
       $res = $this->say_time($time, $escape_digits);
       if($res['code'] == AGIRES_OK && $res['result'] > 0)
         $buffer .= chr($res['result']);
       return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}));
   }

   /**
    * Play the given audio file, allowing playback to be interrupted by a DTMF digit. This command is similar to the GET DATA
    * command but this command returns after the first DTMF digit has been pressed while GET DATA can accumulated any number of
    * digits before returning.
    * Return early if $buffer is adequate for request.
    *
    * @link http://www.voip-info.org/wiki-stream+file
    * @param string $buffer
    * @param string $filename without extension, often in /var/lib/asterisk/sounds
    * @param string $escape_digits
    * @param integer $offset
    * @return array, see evaluate for return information. ['result'] is -1 on hangup or error, 0 if playback completes with no
    * digit received, otherwise a decimal value of the DTMF tone.  Use chr() to convert to ASCII.
    */
   function fastpass_stream_file(&$buffer, $filename, $escape_digits='', $offset=0)
   {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
       if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
         $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
       $res = $this->stream_file($filename, $escape_digits, $offset);
       if($res['code'] == AGIRES_OK && $res['result'] > 0)
         $buffer .= chr($res['result']);
       return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}), 'endpos'=>0);
   }

   /**
    * Use festival to read text.
    * Return early if $buffer is adequate for request.
    *
    * @link http://www.cstr.ed.ac.uk/projects/festival/
    * @param string $buffer
    * @param string $text
    * @param string $escape_digits
    * @param integer $frequency
    * @return array, see evaluate for return information.
    */
   function fastpass_text2wav(&$buffer, $text, $escape_digits='', $frequency=8000)
   {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
       if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
         $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
       $res = $this->text2wav($text, $escape_digits, $frequency);
       if($res['code'] == AGIRES_OK && $res['result'] > 0)
         $buffer .= chr($res['result']);
       return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}), 'endpos'=>0);
   }

   /**
    * Use Cepstral Swift to read text.
    * Return early if $buffer is adequate for request.
    *
    * @link http://www.cepstral.com/
    * @param string $buffer
    * @param string $text
    * @param string $escape_digits
    * @param integer $frequency
    * @return array, see evaluate for return information.
    */
   function fastpass_swift(&$buffer, $text, $escape_digits='', $frequency=8000, $voice=NULL)
   {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
       if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
         $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
       $res = $this->swift($text, $escape_digits, $frequency, $voice);
       if($res['code'] == AGIRES_OK && $res['result'] > 0)
         $buffer .= chr($res['result']);
       return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}), 'endpos'=>0);
   }

   /**
    * Say Puncutation in a string.
    * Return early if $buffer is adequate for request.
    *
    * @param string $buffer
    * @param string $text
    * @param string $escape_digits
    * @param integer $frequency
    * @return array, see evaluate for return information.
    */
   function fastpass_say_punctuation(&$buffer, $text, $escape_digits='', $frequency=8000)
   {
     $proceed = false;
     if($escape_digits != '' && $buffer != '')
     {
       if(!strpos(chr(255) . $escape_digits, $buffer{strlen($buffer)-1}))
         $proceed = true;
     }
     if($buffer == '' || $proceed)
     {
       $res = $this->say_punctuation($text, $escape_digits, $frequency);
       if($res['code'] == AGIRES_OK && $res['result'] > 0)
         $buffer .= chr($res['result']);
       return $res;
     }
     return array('code'=>AGIRES_OK, 'result'=>ord($buffer{strlen($buffer)-1}));
   }

   /**
    * Plays the given file and receives DTMF data.
    * Return early if $buffer is adequate for request.
    *
    * This is similar to STREAM FILE, but this command can accept and return many DTMF digits,
    * while STREAM FILE returns immediately after the first DTMF digit is detected.
    *
    * Asterisk looks for the file to play in /var/lib/asterisk/sounds by default.
    *
    * If the user doesn't press any keys when the message plays, there is $timeout milliseconds
    * of silence then the command ends.
    *
    * The user has the opportunity to press a key at any time during the message or the
    * post-message silence. If the user presses a key while the message is playing, the
    * message stops playing. When the first key is pressed a timer starts counting for
    * $timeout milliseconds. Every time the user presses another key the timer is restarted.
    * The command ends when the counter goes to zero or the maximum number of digits is entered,
    * whichever happens first.
    *
    * If you don't specify a time out then a default timeout of 2000 is used following a pressed
    * digit. If no digits are pressed then 6 seconds of silence follow the message.
    *
    * If you don't specify $max_digits then the user can enter as many digits as they want.
    *
    * Pressing the # key has the same effect as the timer running out: the command ends and
    * any previously keyed digits are returned. A side effect of this is that there is no
    * way to read a # key using this command.
    *
    * @link http://www.voip-info.org/wiki-get+data
    * @param string $buffer
    * @param string $filename file to play. Do not include file extension.
    * @param integer $timeout milliseconds
    * @param integer $max_digits
    * @return array, see evaluate for return information. ['result'] holds the digits and ['data'] holds the timeout if present.
    *
    * This differs from other commands with return DTMF as numbers representing ASCII characters.
    */
   function fastpass_get_data(&$buffer, $filename, $timeout=NULL, $max_digits=NULL)
   {
     if(is_null($max_digits) || strlen($buffer) < $max_digits)
     {
       if($buffer == '')
       {
         $res = $this->get_data($filename, $timeout, $max_digits);
         if($res['code'] == AGIRES_OK)
           $buffer .= $res['result'];
         return $res;
       }
       else
       {
         while(is_null($max_digits) || strlen($buffer) < $max_digits)
         {
           $res = $this->wait_for_digit();
           if($res['code'] != AGIRES_OK) return $res;
           if($res['result'] == ord('#')) break;
           $buffer .= chr($res['result']);
         }
       }
     }
     return array('code'=>AGIRES_OK, 'result'=>$buffer);
   }

   // *********************************************************************************************************
   // **                       DERIVED                                                                       **
   // *********************************************************************************************************

   /**
    * Menu.
    *
    * This function presents the user with a menu and reads the response
    *
    * @param array $choices has the following structure:
    *   array('1'=>'*Press 1 for this', // festival reads if prompt starts with *
    *         '2'=>'some-gsm-without-extension',
    *         '*'=>'*Press star for help');
    * @return mixed key pressed on sucess, -1 on failure
    */
    function menu($choices, $timeout=2000)
    {
      $keys = join('', array_keys($choices));
      $choice = NULL;
      while(is_null($choice))
      {
        foreach($choices as $prompt)
        {
          if($prompt{0} == '*')
            $ret = $this->text2wav(substr($prompt, 1), $keys);
          else
            $ret = $this->stream_file($prompt, $keys);

          if($ret['code'] != AGIRES_OK || $ret['result'] == -1)
          {
            $choice = -1;
            break;
          }

          if($ret['result'] != 0)
          {
            $choice = chr($ret['result']);
            break;
          }
        }

        if(is_null($choice))
        {
          $ret = $this->get_data('beep', $timeout, 1);
          if($ret['code'] != AGIRES_OK || $ret['result'] == -1)
            $choice = -1;
          elseif($ret['result'] != '' && strpos(' '.$keys, $ret['result']))
            $choice = $ret['result'];
        }
      }
      return $choice;
    }

   /**
    * Goto_dest - Set context, extension and priority.
    *
    * @param string $context
    * @param string $extension
    * @param string $priority
    */
    function goto_dest($context, $extension='s', $priority=1)
    {
      $this->set_context($context);
      $this->set_extension($extension);
      $this->set_priority($priority);
    }

   /**
    * Parse caller id.
    *
    * @example examples/dtmf.php Get DTMF tones from the user and say the digits
    * @example examples/input.php Get text input from the user and say it back
    *
    * "name" <proto:user@server:port>
    *
    * @param string $callerid
    * @return array('Name'=>$name, 'Number'=>$number)
    */
    function parse_callerid($callerid=NULL)
    {
      if(is_null($callerid))
        $callerid = $this->request['agi_callerid'];

      $ret = array('name'=>'', 'protocol'=>'', 'username'=>'', 'host'=>'', 'port'=>'');
      $callerid = trim($callerid);

      if($callerid{0} == '"' || $callerid{0} == "'")
      {
        $d = $callerid{0};
        $callerid = explode($d, substr($callerid, 1));
        $ret['name'] = array_shift($callerid);
        $callerid = join($d, $callerid);
      }

      $callerid = explode('@', trim($callerid, '<> '));
      $username  = explode(':', array_shift($callerid));
      if(count($username) == 1)
        $ret['username'] = $username[0];
      else
      {
        $ret['protocol'] = array_shift($username);
        $ret['username'] = join(':', $username);
      }

      $callerid = join('@', $callerid);
      $host = explode(':', $callerid);
      if(count($host) == 1)
        $ret['host'] =  $host[0];
      else
      {
        $ret['host'] = array_shift($host);
        $ret['port'] = join(':', $host);
      }

      return $ret;
    }

   /**
    * Use festival to read text.
    *
    * @example examples/dtmf.php Get DTMF tones from the user and say the digits
    * @example examples/input.php Get text input from the user and say it back
    * @example examples/ping.php Ping an IP address
    *
    * @link http://www.cstr.ed.ac.uk/projects/festival/
    * @param string $text
    * @param string $escape_digits
    * @param integer $frequency
    * @return array, see evaluate for return information.
    */
    function text2wav($text, $escape_digits='', $frequency=8000)
    {
      // festival TTS config
      if(!isset($this->config['festival']['text2wave'])) $this->config['festival']['text2wave'] = $this->which('text2wave');

      $text = trim($text);
      if($text == '') return true;

      $hash = md5($text);
      $fname = $this->config['phpagi']['tempdir'] . DIRECTORY_SEPARATOR;
      $fname .= 'text2wav_' . $hash;

      // create wave file
      if(!file_exists("$fname.wav"))
      {
        // write text file
        if(!file_exists("$fname.txt"))
        {
          $fp = fopen("$fname.txt", 'w');
          fputs($fp, $text);
          fclose($fp);
        }

        shell_exec("{$this->config['festival']['text2wave']} -F $frequency -o $fname.wav $fname.txt");
      }
      else
      {
        touch("$fname.txt");
        touch("$fname.wav");
      }

      // stream it
      $ret = $this->stream_file($fname, $escape_digits);

      // clean up old files
      $delete = time() - 2592000; // 1 month
      foreach(glob($this->config['phpagi']['tempdir'] . DIRECTORY_SEPARATOR . 'text2wav_*') as $file)
        if(filemtime($file) < $delete)
          unlink($file);

      return $ret;
    }

   /**
    * Use Cepstral Swift to read text.
    *
    * @link http://www.cepstral.com/
    * @param string $text
    * @param string $escape_digits
    * @param integer $frequency
    * @return array, see evaluate for return information.
    */
    function swift($text, $escape_digits='', $frequency=8000, $voice=NULL)
    {
      // swift TTS config
      if(!isset($this->config['cepstral']['swift'])) $this->config['cepstral']['swift'] = $this->which('swift');

      if(!is_null($voice))
        $voice = "-n $voice";
      elseif(isset($this->config['cepstral']['voice']))
        $voice = "-n {$this->config['cepstral']['voice']}";

      $text = trim($text);
      if($text == '') return true;

      $hash = md5($text);
      $fname = $this->config['phpagi']['tempdir'] . DIRECTORY_SEPARATOR;
      $fname .= 'swift_' . $hash;

      // create wave file
      if(!file_exists("$fname.wav"))
      {
        // write text file
        if(!file_exists("$fname.txt"))
        {
          $fp = fopen("$fname.txt", 'w');
          fputs($fp, $text);
          fclose($fp);
        }

        shell_exec("{$this->config['cepstral']['swift']} -p audio/channels=1,audio/sampling-rate=$frequency $voice -o $fname.wav -f $fname.txt");
      }

      // stream it
      $ret = $this->stream_file($fname, $escape_digits);

      // clean up old files
      $delete = time() - 2592000; // 1 month
      foreach(glob($this->config['phpagi']['tempdir'] . DIRECTORY_SEPARATOR . 'swift_*') as $file)
        if(filemtime($file) < $delete)
          unlink($file);

      return $ret;
    }

   /**
    * Text Input.
    *
    * Based on ideas found at http://www.voip-info.org/wiki-Asterisk+cmd+DTMFToText
    *
    * Example:
    *              UC   H     LC   i      ,     SP   h     o      w    SP   a    r      e     SP   y      o      u     ?
    *   $string = '*8'.'44*'.'*5'.'444*'.'00*'.'0*'.'44*'.'666*'.'9*'.'0*'.'2*'.'777*'.'33*'.'0*'.'999*'.'666*'.'88*'.'0000*';
    *
    * @link http://www.voip-info.org/wiki-Asterisk+cmd+DTMFToText
    * @example examples/input.php Get text input from the user and say it back
    *
    * @return string
    */
    function text_input($mode='NUMERIC')
    {
      $alpha = array( 'k0'=>' ', 'k00'=>',', 'k000'=>'.', 'k0000'=>'?', 'k00000'=>'0',
                      'k1'=>'!', 'k11'=>':', 'k111'=>';', 'k1111'=>'#', 'k11111'=>'1',
                      'k2'=>'A', 'k22'=>'B', 'k222'=>'C', 'k2222'=>'2',
                      'k3'=>'D', 'k33'=>'E', 'k333'=>'F', 'k3333'=>'3',
                      'k4'=>'G', 'k44'=>'H', 'k444'=>'I', 'k4444'=>'4',
                      'k5'=>'J', 'k55'=>'K', 'k555'=>'L', 'k5555'=>'5',
                      'k6'=>'M', 'k66'=>'N', 'k666'=>'O', 'k6666'=>'6',
                      'k7'=>'P', 'k77'=>'Q', 'k777'=>'R', 'k7777'=>'S', 'k77777'=>'7',
                      'k8'=>'T', 'k88'=>'U', 'k888'=>'V', 'k8888'=>'8',
                      'k9'=>'W', 'k99'=>'X', 'k999'=>'Y', 'k9999'=>'Z', 'k99999'=>'9');
      $symbol = array('k0'=>'=',
                      'k1'=>'<', 'k11'=>'(', 'k111'=>'[', 'k1111'=>'{', 'k11111'=>'1',
                      'k2'=>'@', 'k22'=>'$', 'k222'=>'&', 'k2222'=>'%', 'k22222'=>'2',
                      'k3'=>'>', 'k33'=>')', 'k333'=>']', 'k3333'=>'}', 'k33333'=>'3',
                      'k4'=>'+', 'k44'=>'-', 'k444'=>'*', 'k4444'=>'/', 'k44444'=>'4',
                      'k5'=>"'", 'k55'=>'`', 'k555'=>'5',
                      'k6'=>'"', 'k66'=>'6',
                      'k7'=>'^', 'k77'=>'7',
                      'k8'=>"\\",'k88'=>'|', 'k888'=>'8',
                      'k9'=>'_', 'k99'=>'~', 'k999'=>'9');
      $text = '';
      do
      {
        $command = false;
        $result = $this->get_data('beep');
        foreach(explode('*', $result['result']) as $code)
        {
          if($command)
          {
            switch($code{0})
            {
              case '2': $text = substr($text, 0, strlen($text) - 1); break; // backspace
              case '5': $mode = 'LOWERCASE'; break;
              case '6': $mode = 'NUMERIC'; break;
              case '7': $mode = 'SYMBOL'; break;
              case '8': $mode = 'UPPERCASE'; break;
              case '9': $text = explode(' ', $text); unset($text[count($text)-1]); $text = join(' ', $text); break; // backspace a word
            }
            $code = substr($code, 1);
            $command = false;
          }
          if($code == '')
            $command = true;
          elseif($mode == 'NUMERIC')
            $text .= $code;
          elseif($mode == 'UPPERCASE' && isset($alpha['k'.$code]))
            $text .= $alpha['k'.$code];
          elseif($mode == 'LOWERCASE' && isset($alpha['k'.$code]))
            $text .= strtolower($alpha['k'.$code]);
          elseif($mode == 'SYMBOL' && isset($symbol['k'.$code]))
            $text .= $symbol['k'.$code];
        }
        $this->say_punctuation($text);
      } while(substr($result['result'], -2) == '**');
      return $text;
    }

   /**
    * Say Puncutation in a string.
    *
    * @param string $text
    * @param string $escape_digits
    * @param integer $frequency
    * @return array, see evaluate for return information.
    */
    function say_punctuation($text, $escape_digits='', $frequency=8000)
    {
      for($i = 0; $i < strlen($text); $i++)
      {
        switch($text{$i})
        {
          case ' ': $ret .= 'SPACE ';
          case ',': $ret .= 'COMMA '; break;
          case '.': $ret .= 'PERIOD '; break;
          case '?': $ret .= 'QUESTION MARK '; break;
          case '!': $ret .= 'EXPLANATION POINT '; break;
          case ':': $ret .= 'COLON '; break;
          case ';': $ret .= 'SEMICOLON '; break;
          case '#': $ret .= 'POUND '; break;
          case '=': $ret .= 'EQUALS '; break;
          case '<': $ret .= 'LESS THAN '; break;
          case '(': $ret .= 'LEFT PARENTHESIS '; break;
          case '[': $ret .= 'LEFT BRACKET '; break;
          case '{': $ret .= 'LEFT BRACE '; break;
          case '@': $ret .= 'AT '; break;
          case '$': $ret .= 'DOLLAR SIGN '; break;
          case '&': $ret .= 'AMPERSAND '; break;
          case '%': $ret .= 'PERCENT '; break;
          case '>': $ret .= 'GREATER THAN '; break;
          case ')': $ret .= 'RIGHT PARENTHESIS '; break;
          case ']': $ret .= 'RIGHT BRACKET '; break;
          case '}': $ret .= 'RIGHT BRACE '; break;
          case '+': $ret .= 'PLUS '; break;
          case '-': $ret .= 'MINUS '; break;
          case '*': $ret .= 'ASTERISK '; break;
          case '/': $ret .= 'SLASH '; break;
          case "'": $ret .= 'SINGLE QUOTE '; break;
          case '`': $ret .= 'BACK TICK '; break;
          case '"': $ret .= 'QUOTE '; break;
          case '^': $ret .= 'CAROT '; break;
          case "\\": $ret .= 'BACK SLASH '; break;
          case '|': $ret .= 'BAR '; break;
          case '_': $ret .= 'UNDERSCORE '; break;
          case '~': $ret .= 'TILDE '; break;
          default: $ret .= $text{$i} . ' '; break;
        }
      }
      return $this->text2wav($ret, $escape_digits, $frequency);
    }

   /**
    * Create a new AGI_AsteriskManager.
    */
    function &new_AsteriskManager()
    {
      $this->asm = new AGI_AsteriskManager(NULL, $this->config);
      $this->asm->pagi =& $this;
      $this->config =& $this->asm->config;
      return $this->asm;
    }


   // *********************************************************************************************************
   // **                       PRIVATE                                                                       **
   // *********************************************************************************************************

   /**
    * Evaluate an AGI command.
    *
    * @access private
    * @param string $command
    * @return array ('code'=>$code, 'result'=>$result, 'data'=>$data)
    */
    function evaluate($command)
    {
      $broken = array('code'=>500, 'result'=>-1, 'data'=>'');

      // write command
      if(is_null($this->socket))
      {
        if(!@fwrite($this->out, trim($command) . "\n")) return $broken;
        fflush($this->out);
      }
      elseif(socket_write($this->socket, trim($command) . "\n") === false) return $broken;

      // Read result.  Occasionally, a command return a string followed by an extra new line.
      // When this happens, our script will ignore the new line, but it will still be in the
      // buffer.  So, if we get a blank line, it is probably the result of a previous
      // command.  We read until we get a valid result or asterisk hangs up.  One offending
      // command is SEND TEXT.
      $count = 0;
      do
      {
        $str = is_null($this->socket) ? @fgets($this->in, 4096) : @socket_read($this->socket, 4096, PHP_NORMAL_READ);
      } while($str == '' && $count++ < 5);

      if($count >= 5)
      {
//        $this->conlog("evaluate error on read for $command");
        return $broken;
      }

      // parse result
      $ret['code'] = substr($str, 0, 3);
      $str = trim(substr($str, 3));

      if($str{0} == '-') // we have a multiline response!
      {
        $count = 0;
        $str = substr($str, 1) . "\n";

        $line = is_null($this->socket) ? @fgets($this->in, 4096) : @socket_read($this->socket, 4096, PHP_NORMAL_READ);
        while(substr($line, 0, 3) != $ret['code'] && $count < 5)
        {
          $str .= $line;
          $line = is_null($this->socket) ? @fgets($this->in, 4096) : @socket_read($this->socket, 4096, PHP_NORMAL_READ);
          $count = (trim($line) == '') ? $count + 1 : 0;
        }
        if($count >= 5)
        {
//          $this->conlog("evaluate error on multiline read for $command");
          return $broken;
        }
      }

      $ret['result'] = NULL;
      $ret['data'] = '';
      if($ret['code'] != AGIRES_OK) // some sort of error
      {
        $ret['data'] = $str;
        $this->conlog(print_r($ret, true));
      }
      else // normal AGIRES_OK response
      {
        $parse = explode(' ', trim($str));
        $in_token = false;
        foreach($parse as $token)
        {
          if($in_token) // we previously hit a token starting with '(' but not ending in ')'
          {
	    $tmp = trim($token);
	    $tmp = $tmp{0} == '(' ? substr($tmp,1):$tmp;
	    $tmp = substr($tmp,-1) == ')' ? substr($tmp,0,strlen($tmp)-1):$tmp;
	    $ret['data'] .= ' ' . trim($tmp);
            if($token{strlen($token)-1} == ')') $in_token = false;
          }
          elseif($token{0} == '(')
          {
            if($token{strlen($token)-1} != ')') $in_token = true;
	    $tmp = trim(substr($token,1));
	    $tmp = $in_token ? $tmp : substr($tmp,0,strlen($tmp)-1);
	    $ret['data'] .= ' ' . trim($tmp);
          }
          elseif(strpos($token, '='))
          {
            $token = explode('=', $token);
            $ret[$token[0]] = $token[1];
          }
          elseif($token != '')
            $ret['data'] .= ' ' . $token;
        }
        $ret['data'] = trim($ret['data']);
      }

      // log some errors
      if($ret['result'] < 0)
        $this->conlog("$command returned {$ret['result']}");

      return $ret;
    }

   /**
    * Log to console if debug mode.
    *
    * @example examples/ping.php Ping an IP address
    *
    * @param string $str
    * @param integer $vbl verbose level
    */
    function conlog($str, $vbl=1) {
      static $busy = false;

      if(isset($this->config['phpagi'], $this->config['phpagi']['debug']) && $this->config['phpagi']['debug'] != false) {
        if(!$busy) { // no conlogs inside conlog!!!
          $busy = true;
          $this->verbose($str, $vbl);
          $busy = false;
        }
      }
    }

   /**
    * Find an execuable in the path.
    *
    * @access private
    * @param string $cmd command to find
    * @param string $checkpath path to check
    * @return string the path to the command
    */
    function which($cmd, $checkpath=NULL)
    {
      global $_ENV;
      $chpath = is_null($checkpath) ? $_ENV['PATH'] : $checkpath;

      foreach(explode(PATH_SEPERATOR, $chpath) as $path)
        if(!function_exists('is_executable') || is_executable($path . DIRECTORY_SEPERATOR . $cmd))
          return $path . DIRECTORY_SEPERATOR . $cmd;

      if(is_null($checkpath))
      {
        if(substr(strtoupper(PHP_OS, 0, 3)) != 'WIN')
          return $this->which($cmd, '/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:'.
                                    '/usr/X11R6/bin:/usr/local/apache/bin:/usr/local/mysql/bin');
      }
      return false;
    }

   /**
    * Make a folder recursively.
    *
    * @access private
    * @param string $folder
    * @param integer $perms
    */
    function make_folder($folder, $perms=0755)
    {
      $f = explode(DIRECTORY_SEPARATOR, $folder);
      $base = '';
      for($i = 0; $i < count($f); $i++)
      {
        $base .= $f[$i];
        if($f[$i] != '' && !file_exists($base))
          mkdir($base, $perms);
        $base .= DIRECTORY_SEPARATOR;
      }
    }	
  }

/**
 * error handler for phpagi.
 *
 * @param integer $level PHP error level
 * @param string $message error message
 * @param string $file path to file
 * @param integer $line line number of error
 * @param array $context variables in the current scope
 */
  function phpagi_error_handler($level, $message, $file, $line, $context)
  {
    if(ini_get('error_reporting') == 0) return; // this happens with an @

    @syslog(LOG_WARNING, $file . '[' . $line . ']: ' . $message);

    global $phpagi_error_handler_email;
    if(function_exists('mail') && !is_null($phpagi_error_handler_email)) // generate email debugging information
    {
      // decode error level
      switch($level)
      {
        case E_WARNING:
        case E_USER_WARNING:
          $level = "Warning";
          break;
        case E_NOTICE:
        case E_USER_NOTICE:
          $level = "Notice";
          break;
        case E_USER_ERROR:
          $level = "Error";
          break;
      }

      // build message
      $basefile = basename($file);
      $subject = "$basefile/$line/$level: $message";
      $message = "$level: $message in $file on line $line\n\n";

      if(function_exists('mysql_errno') && strpos(' '.strtolower($message), 'mysql'))
        $message .= 'MySQL error ' . mysql_errno() . ": " . mysql_error() . "\n\n";

      // figure out who we are
      if(function_exists('socket_create'))
      {
        $addr = NULL;
        $port = 80;
        $socket = @socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
        @socket_connect($socket, '64.0.0.0', $port);
        @socket_getsockname($socket, $addr, $port);
        @socket_close($socket);
        $message .= "\n\nIP Address: $addr\n";
      }

      // include variables
      $message .= "\n\nContext:\n" . print_r($context, true);
      $message .= "\n\nGLOBALS:\n" . print_r($GLOBALS, true);
      $message .= "\n\nBacktrace:\n" . print_r(debug_backtrace(), true);

      // include code fragment
      if(file_exists($file))
      {
        $message .= "\n\n$file:\n";
        $code = @file($file);
        for($i = max(0, $line - 10); $i < min($line + 10, count($code)); $i++)
          $message .= ($i + 1)."\t$code[$i]";
      }

      // make sure message is fully readable (convert unprintable chars to hex representation)
      $ret = '';
      for($i = 0; $i < strlen($message); $i++)
      {
        $c = ord($message{$i});
        if($c == 10 || $c == 13 || $c == 9)
          $ret .= $message{$i};
        elseif($c < 16)
          $ret .= '\x0' . dechex($c);
        elseif($c < 32 || $c > 127)
          $ret .= '\x' . dechex($c);
        else
          $ret .= $message{$i};
      }
      $message = $ret;

      // send the mail if less than 5 errors
      static $mailcount = 0;
      if($mailcount < 5)
        @mail($phpagi_error_handler_email, $subject, $message);
      $mailcount++;
    }
  }
  $phpagi_error_handler_email = NULL;
?>