The Phar stream wrapper fully supports fopen() for read and write (not append), unlink(), stat(), fstat(), fseek(), rename() and directory stream operations opendir() and as of version 2.0.0, rmdir() and mkdir().
Individual file compression and per-file metadata can also be manipulated in a Phar archive using stream contexts:
$context = stream_context_create(array('phar' =>
array('compress' => Phar::GZ)),
array('metadata' => array('user' => 'cellog')));
file_put_contents('phar://my.phar/somefile.php', 0, $context);
Although it is possible to create phar archives from scratch just using stream operations, it is best to use the functionality built into the Phar class. The stream wrapper is best used for read-only operations.