(PHP 5 >= 5.2.0, PECL zip >= 1.1.0)
ZipArchive::getArchiveComment — Returns the Zip archive comment
$flags
  ] )Returns the Zip archive comment.
flags
       If flags is set to ZipArchive::FL_UNCHANGED, the original unchanged
       comment is returned.
      
   Returns the Zip archive comment or FALSE on failure.
  
Example #1 Dump an archive comment
<?php
$zip = new ZipArchive;
$res = $zip->open('test_with_comment.zip');
if ($res === TRUE) {
    var_dump($zip->getArchiveComment());
    /* Or using the archive property */
    var_dump($zip->comment);
} else {
    echo 'failed, code:' . $res;
}
?>