C.D.C. - NagiosXI Plugin - Unfinished

//Custom Disk Check
<?php
//
//Basic Knowledge Of Script
define("PROGRAM","custom_disk_check");
define("VERSION", "0.0.1");
define("STATUS_OK", 0);
define("STATUS_WARNING", 1);
define("STATUS_CRITICAL", 2);
define("STATUS_UNKNOWN", 3);
//
//Specification Arguments
$host = "";
$port = "";
$user = "";
$password = "";
$path = "";
$warn = "";
$crit = "";
$mode = ""; // Warning: Make Sure That The Units You Use Here (In Mode), You Use In Warning & Critical.. You will get an error if you do not do so
//
//Nagios print out, status..
function nagios_print($stdout = '', $exitcode=0) {
    print($stdout);
    exit($exitcode);
}
//
//Let's hope this never happens but..
//In case it does, it must be here.. Prints out error message
function plugin_error($errmessage)
{

    print("***ERROR***:\n\n{$errmessage}\n\n")
    usage();
    nagios_print("", STATUS_UNKNOWN);

}
//
//Selects Unit Mode Based Off Of Set Variable
function unitMode($unit)
{

  global $mode;
  $unitModes = array('precent', 'kb', 'mb', 'gb', 'tb');

  switch($mode)
  {

  case 'precent':
     $unit = '%';
      break;

  case 'kb':
     $unit = 'KB';
      break;

  case 'gb':
     $unit = 'GB';
      break;

  case 'tb':
     $unit = 'TB';
      break;

   case 'mb':
     $unit = 'MB';
      break;

   default:
     $unit = 'MB';

   }

   return $unit;

}
//
//Normal disk stats in either kB, MB, GB, or TB
function disk_stat($path)
{

  global $mode, $path;

  //Gets disk space(s)
  $freespace = disk_free_space($path);
  $totalspace = disk_total_space($path);

  $uunit = unitMode($mode);
  $status = SetStatus($freespace);

  if ($uunit == '%')
  {
    nagios_print('You have '.(($freespace / $totalspace) * 100) .$uunit 'of free space', $status );
  }
  else
  {
    nagios_print('Total Space:\n'.$totalspace .$uunit '\nFree Space:\n'.$freespace .$uunit, $status);
  }

}
//
//If sentence to specify status of the nagios output
function SetStatus($freespace)
{

  global $warn, $crit;

  $status = STATUS_UNKNOWN;

  if($freespace > $warn)
  {
        $status = STATUS_OK; //Ok Status
  }
  else if($freespace <= $warn && $freespace > $crit)
  {
        $status = STATUS_WARNING; // Warning Status
  }
  else if($freespace <= $crit)
  {
        $status = STATUS_CRITICAL; // Critical Status duh..
  }

  return $status;

}
//
//Prints out HowToUse this script
function usage()
{

  print(" \n
  Usage: ".PROGRAM." -h | -d <domain> [-c <critical>] [-w <warning>] [-s <whoisServer>]
  NOTE: host, port, path, need to be specified!

  Options:
  -host
       Enter IP Of The Host

  -port
       Enter Port Of The Host

  -user
       Enter Username

  -password
       Enter Password

  -path
       Enter Path Of The Partition

  -warn
       Enter Warning Value To Get Warned Whenever The Disk Reaches That Value.
       NOTE: The Value Should Be In The Unit You Are Going To Use In Mode Parameter.

  -crit
       Enter Critical Value To Get Warned Whenever The Disk Reaches That Value.
       NOTE: The Value Should Be In The Unit You Are Going To Use In Mode Parameter.

  -mode
       Enter Mode To Use Specific Unit ['precent','kb','mb','gb','tb']

  This plugin will use the PHP command to check disk space of certain server.
  Example:
       $./".PROGRAM." -host 127.0.0.1 -port 22 -user admin -password admin123 -path /root -warn 80 -crit 90 -mode precent

        \n ");

}

function error()
{

}

function Connect()
{
  global $host, $port, $user, $password;

  $connection = ssh2_connect($host, $port);
  ssh2_auth_password($connection, $user, $password);
  $stream = ssh2_exec($connection, 'hostname');
  echo "Output: " . stream_get_contents($stream);

}

function Main()
{

  Connect();

    disk_stat($path);

}

        Main(); //Should work shouln't it?

?>