(PECL eio >= 0.0.1dev)
eio_fchown — Change file ownership
$fd
   , int $uid
   [, int $gid = -1
   [, int $pri = EIO_PRI_DEFAULT
   [, callable $callback = NULL
   [, mixed $data = NULL
  ]]]] )
   eio_fchown() changes ownership of the file specified by
   fd file descriptor.
  
fdStream, Socket resource, or numeric file descriptor.
uidUser ID. Is ignored when equal to -1.
gidGroup ID. Is ignored when equal to -1.
priThe request priority: EIO_PRI_DEFAULT, EIO_PRI_MIN, EIO_PRI_MAX, or NULL.
If NULL passed, pri internally is set to
EIO_PRI_DEFAULT.
callback
callback function is called when the request is done.
It should match the following prototype: 
void callback(mixed $data, int $result[, resource $req]);
datais custom data passed to the request.
resultrequest-specific result value; basically, the value returned by corresponding system call.
reqis optional request resource which can be used with functions like eio_get_last_error()
data
     Arbitrary variable passed to callback.