Time limit thingy for ubuntu

throwhimoff.php

#!/usr/bin/php
<?php
define("target","daniel");
define("maxtime",60); // per day
define("pidfile","/var/run/throwyaoff.pid");
define("timefile","/etc/time");
if(posix_getuid() != 0) die("Run as root" . PHP_EOL);
if($argc == 1) die($argv[0] . " <\033[34mcommand\033[0m>" . PHP_EOL . "Where \033[34mcommand\033[0m is one of \033[32mreset\033[0m, \033[32mstart\033[0m, \033[32mstop\033[0m or \033[32mrestart\033[0m." . PHP_EOL);
if($argv[1] == "restart") posix_kill(getrunningpid(),SIGUSR2);
if($argv[1] == "start" || $argv[1] == "restart")
{
  $pid = pcntl_fork();
  if ($pid == -1)
  {
      die('could not fork');
  }
  else if ($pid)
  {
    exit;
    // we are the parent
    //pcntl_wait($status); //Protect against Zombie children
  }
  else
  {
    if(is_link(pidfile) && !is_dir(pidfile))
    {
      echo "Removed old, unused pidfile" . PHP_EOL;
      unlink(pidfile);
    }
    if(is_link(pidfile) && is_dir(pidfile)) die("Already running as PID " . getrunningpid() . PHP_EOL);
    if (@symlink("/proc/" . posix_getpid(), pidfile) !==  FALSE)
    {
       register_shutdown_function('unlink', pidfile);
       echo "Alright, successfully forked to " . posix_getpid() . " and locked the lockfile." . PHP_EOL;
       declare(ticks = 1);
       pcntl_signal(SIGUSR2, "stop");
       pcntl_signal(SIGUSR1, "rst");
       $alerts = Array();
       $ot = file_get_contents(timefile);
       $tim = fopen(timefile,"w+") or die("Couldn't open timefile for reading and writing" . PHP_EOL);
       settime($ot);
       if(filemtime(timefile) < time()-(date("H")*60*60+date("i")*60+date("s"))) rst();
       if(gettime() == "") rst();
       while(true)
       {
         if(date("Hi") == 0001) rst();
         sleep(60);
         if(
         explode(" ",explode("\n",shell_exec("DISPLAY=':0' xset -q|grep 'Monitor is'"))[0])[4] == "On"
         && in_array(target,explode("\n",shell_exec("ps axu | grep 'gnome-session --session' | grep -v grep | awk ' { print $1 } '"))))
         {
           if(gettime() >= maxtime) throwout();
           elseif(gettime() >= maxtime-5) alert(5);
           elseif(gettime() >= maxtime-15) alert(15);
           settime(gettime()+1);
         }
       }
    }
    else
    {
      die("Couldn't lock " . pidfile . PHP_EOL);
    }
  }
}
elseif($argv[1] == "stop")
{
  posix_kill(getrunningpid(),SIGUSR2);
}
elseif($argv[1] == "reset")
{
  posix_kill(getrunningpid(),SIGUSR1);
}
function getrunningpid()
{
  return @explode("/",@readlink(pidfile))[2];
}
function stop()
{
  exit;
  posix_kill(posix_getpid());
}
function rst()
{
  file_put_contents(timefile,0);
}
function gettime()
{
  fseek($GLOBALS['tim'],0);
  $t = (int) fread($GLOBALS['tim'],1024);
  return $t;
}
function settime($t)
{
  fseek($GLOBALS['tim'],0);
  return fwrite($GLOBALS['tim'],$t);
}
function throwout()
{
  shell_exec("su " . target . " -c 'kill -9 -1'");
  $alerts = Array();
}
function alert($tt)
{
  if(!in_array($tt,$GLOBALS['alerts']))
  {
    $GLOBALS['alerts'][] = $tt;
    $ti = maxtime-gettime();
    shell_exec("zenity --warning --title Throwhimhoff --text '<span foreground=\"red\" font=\"32\">Abmeldung in (ca) {$ti} Minuten!</span>' > /dev/null 2>&1 &");
  }
}