(PECL eio >= 0.0.1dev)
eio_statvfs — Get file system statistics
  eio_statvfs() returns file system statistics information in
  result argument of callback
  
pathPathname of any file within the mounted file system
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.
     
  eio_statvfs() returns request resource on success or
  FALSE on error. On success assigns result argument of
  callback to an array.
  
Example #1 eio_statvfs() example
<?php
$tmp_filename = '/tmp/eio-file.tmp';
touch($tmp_filename);
function my_statvfs_callback($data, $result) {
    var_dump($data);
    var_dump($result);
 @unlink($data);
}
eio_statvfs($tmp_filename, EIO_PRI_DEFAULT, "my_statvfs_callback", $tmp_filename);
eio_event_loop();
?>
The above example will output something similar to:
string(17) "/tmp/eio-file.tmp"
array(11) {
  ["f_bsize"]=>
  int(4096)
  ["f_frsize"]=>
  int(4096)
  ["f_blocks"]=>
  int(262144)
  ["f_bfree"]=>
  int(262111)
  ["f_bavail"]=>
  int(262111)
  ["f_files"]=>
  int(1540815)
  ["f_ffree"]=>
  int(1540743)
  ["f_favail"]=>
  int(1540743)
  ["f_fsid"]=>
  int(0)
  ["f_flag"]=>
  int(4102)
  ["f_namemax"]=>
  int(255)
}