PublicPrinterControl/app/Controllers/HomeController.php

<?php
namespace App\Controllers;

use App\Models\HomeModel;
use App\Controller;
use App\Model;

class HomeController extends Controller {

  public function __construct($twig)
  {
    $this->twig = $twig;
    $this->model = new HomeModel;
  }

  public function index(){
    echo $this->twig->render('home.twig', array(
			"messages" => $this->model->getMessages(),
    ));
  }

  public function upload(){
    $name = md5(random_int(1, 10000) . microtime()).md5(random_int(1, 10000) . microtime());
    $address = "/tmp/".$name."/".str_replace(" ", " ", basename( $_FILES['file']['name']));
    $address = substr_replace($address , 'pdf', strrpos($address , '.') +1);
    $targetfolder = __DIR__."/../../public/tmp/".$name ."/";

    exec("mkdir ".$targetfolder);
    $targetfolder = addslashes($targetfolder);
    $targetfolder = $targetfolder . basename( $_FILES['file']['name']) ;

    if(move_uploaded_file($_FILES['file']['tmp_name'], $targetfolder)){
      $targetfolder = str_replace(" ", "\ ", $targetfolder);
      $cmd = "sudo /usr/bin/unoconv --output=".$targetfolder." -f pdf ".$targetfolder;
      exec($cmd);
      echo $this->twig->render('upload.twig', array(
  			"messages" => $this->model->getMessages(),
        "link" => $address
      ));
    }
    else {
      echo "Problem uploading file";
    }
  }
}