Theme and module upload in .zip format and unpack this

Hello,
i have here a php script written with the one module and themes upload and extract can.

<?php
/**
 * Unzip the source_file in the destination dir
 *
 * @param   string      The path to the ZIP-file.
 * @param   string      The path where the zipfile should be unpacked, if false the directory of the zip-file is used
 * @param   boolean     Indicates if the files will be unpacked in a directory with the name of the zip-file (true) or not (false) (only if the destination directory is set to false!)
 * @param   boolean     Overwrite existing files (true) or not (false)
 * 
 * @return  boolean     Succesful or not
 * 
 *  original script location http://de.php.net/manual/de/ref.zip.php
 *  thx to darki777 and nielsvandenberge
 */
$src_file = $_GET['file'];
$uploadpath = $_POST['uploadpath']; //path for upload
$posted_file = $_FILES['file']['type'];
$a = $_FILES['file']['size']; 
$file_type = "application/x-zip-compressed";
$filesize = "1048576"; // 1024byte=1kb, 1024byte*1024=1mb
$upload = $_FILES['file']['tmp_name'];

function unzip($src_file, $dest_dir=false, $create_zip_name_dir=true, $overwrite=true)
{
  if(function_exists("zip_open"))
  {   
      if(!is_resource(zip_open($src_file)))
      { 
          $src_file=dirname($_SERVER['SCRIPT_FILENAME'])."/".$src_file; 
      }
      
      if (is_resource($zip = zip_open($src_file)))
      {          
          $splitter = ($create_zip_name_dir === true) ? "." : "/";
          if ($dest_dir === false) $dest_dir = substr($src_file, 0, strrpos($src_file, $splitter))."/";
         
          // Create the directories to the destination dir if they don't already exist
          create_dirs($dest_dir);

          // For every file in the zip-packet
          while ($zip_entry = zip_read($zip))
          {
            // Now we're going to create the directories in the destination directories
           
            // If the file is not in the root dir
            $pos_last_slash = strrpos(zip_entry_name($zip_entry), "/");
            if ($pos_last_slash !== false)
            {
              // Create the directory where the zip-entry should be saved (with a "/" at the end)
              create_dirs($dest_dir.substr(zip_entry_name($zip_entry), 0, $pos_last_slash+1));
            }

            // Open the entry
            if (zip_entry_open($zip,$zip_entry,"r"))
            {
             
              // The name of the file to save on the disk
              $file_name = $dest_dir.zip_entry_name($zip_entry);
             
              // Check if the files should be overwritten or not
              if ($overwrite === true || $overwrite === false && !is_file($file_name))
              {
                // Get the content of the zip entry
                $fstream = zip_entry_read($zip_entry, zip_entry_filesize($zip_entry));           
                
                if(!is_dir($file_name))            
                file_put_contents($file_name, $fstream );
                // Set the rights
                if(file_exists($file_name))
                {
                    chmod($file_name, 0777);
                }
                else
                {
                    print "<p><span style=\"color:red;\">File is not found!</span></p>";
                }
              }
             
              // Close the entry
              zip_entry_close($zip_entry);
            }      
          }
          // Close the zip-file
          zip_close($zip);
      }
      else
      {
        print '<p>Sorry, Zip Archive is not found?!</p>';
        return false;
      }
     return true;
  }
  else
  {
      if(version_compare(phpversion(), "5.2.0", "<"))
      $infoVersion="(use PHP 5.2.0 or later)";
      
      print "<p>You need to install/enable the php_zip.dll extension $infoVersion</p>"; 
  }
}

function create_dirs($path)
{
  if (!is_dir($path))
  {
    $directory_path = "";
    $directories = explode("/",$path);
    array_pop($directories);
   
    foreach($directories as $directory)
    {
      $directory_path .= $directory."/";
      if (!is_dir($directory_path))
      {
        mkdir($directory_path);
        chmod($directory_path, 0777);
      }
    }
  }
}

/* function bytes($a) on http://www.php.net/manual/de/function.number-format.php#72969 */

function bytes($a) {
    $unim = array("B","KB","MB","GB","TB","PB");
    $c = 0;
    while ($a>=1024) {
        $c++;
        $a = $a/1024;
    }
    return number_format($a,($c ? 2 : 0),",",".")." ".$unim[$c];
}
if ($uploadpath){
if($upload)
   {
   if ($posted_file == $file_type){
if($_FILES['file']['size'] <  $filesize)
      {
      move_uploaded_file($_FILES['file']['tmp_name'], "$uploadpath/".$_FILES['file']['name']);
      print "<p>The file ".$_FILES['file']['name']." is uploaded. Click <a href='".$_SERVER['REQUEST_URI']."?file=".$uploadpath."/".$_FILES['file']['name']."'>here for unpack</a>. </p>";
      
      }

   else
      {
         print "<p>Filesize is ".bytes($a);$a = $filesize; print "! max. allowed ".bytes($a)."!</p>";
      }

    } else {print "<p>Only '".$file_type."' file types allowed.</p>"; }}
    else {print " Change file to upload!";} } if ($upload== "" &$src_file == ""){print " Change Theme or Module!";}
    
if ($src_file) {create_dirs($path); unzip($src_file, $dest_dir=false, $create_zip_name_dir=true, $overwrite=true); print "File is unpacked!";
} else { print'
<form action="" method="post" enctype="multipart/form-data"> <br />
<label><b>Theme:</b> <input type="radio" name="uploadpath" class="form-radio" value="themes" /></label><br />
<label><b>Module:</b> <input type="radio" name="uploadpath" class="form-radio" value="modules" /></label><br />
<label><b>File:</b> <input type="file" name="file" size="40" style="width:14em;"></label><input type="submit" value="Submit"> 
</form>';} ?>

One can build a block with this code or change this to module.