php zipArchive unzip only certain extensions

Question

I'm in need of unziping uploaded content. But for security purposes must verify the files are only image files so that somebody can't add a php into the zip and then run it later.

While doing the unzip I need to preseverve the file structure as well.

$zip->extractTo($save_path . $file_name, array('*.jpg','*.jpeg','*.png','*.gif') );

doesn't return null. Is there a parameter I can use for this or must I iterate with a loop through the zip file using regex to match extensions and create the folders and save the files with code??

Thanks

Answer 1

from php.net, handling .txt files

<?php 
   $value="test.zip"; 
   $filename="zip_files/$value"; 
   $zip = new ZipArchive;
     if ($zip->open($filename) === true) {
      echo "Generating TEXT file.";
          for($i = 0; $i < $zip->numFiles; $i++) { 
             $entry = $zip->getNameIndex($i);
               if(preg_match('#.(txt)$#i', $entry))
                {
                ////This copy function will move the entry to the root of "txt_files" without creating any sub-folders unlike "ZIP->EXTRACTO" function.
                 copy('zip://'.dirname(__FILE__).'/zip_files/'.$value.'#'.$entry, 'txt_files/'.$value.'.txt'); 
                } 
              }  
             $zip->close();
            }
    else{
         echo "ZIP archive failed";
        }
?>