(PECL eio >= 0.0.1dev)
eio_chmod — Change file/direcrory permissions.
$path
   , int $mode
   [, int $pri = EIO_PRI_DEFAULT
   [, callable $callback = NULL
   [, mixed $data = NULL
  ]]] )
   eio_chmod() changes file, or direcrory permissions. The
  new permissions are specified by mode.
  
path
    Path to the target file or directory
Avoid relative paths
mode
    
     The new permissions. E.g. 0644.
     
pri
    The 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]);
data
is custom data passed to the request.
result
request-specific result value; basically, the value returned by corresponding system call.
req
is optional request resource which can be used with functions like eio_get_last_error()
data
    
     Arbitrary variable passed to callback.
     
    eio_chmod() returns request resource on success or FALSE on error.