Description:
------------
The documentation says:

resource shm_attach ( int $key [, int $memsize [, int $perm ]] )

,  what's valid on 5.3, however versions prior to it used to return integer. 

-------
$f=trim(`mktemp`); 
$key=ftok($f,'a'); 
$shm = shm_attach($key, 100000);
var_dump($shm);
unlink($f);
-----------
PHP 5.3.1-5 with Suhosin-Patch (cli) (built: Feb 22 2010 17:37:40) 
Copyright (c) 1997-2009 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2009 Zend Technologies
    with Suhosin v0.9.29, Copyright (c) 2007, by SektionEins GmbH


returns: resource(5) of type (sysvshm)


------------
PHP 5.2.6-1+lenny8 with Suhosin-Patch 0.9.6.2 (cli) (built: Mar 14 2010 08:14:04) 
Copyright (c) 1997-2008 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2008 Zend Technologies
    with Xdebug v2.0.4, Copyright (c) 2002-2008, by Derick Rethans


returns: int(5)


Test script:
---------------
$f=trim(`mktemp`); 
$key=ftok($f,'a'); 
$shm = shm_attach($key, 100000);
var_dump($shm);
unlink($f);