Description:
------------
---
From manual page: http://www.php.net/function.posix-isatty
---
Although documentation says "Returns TRUE if fd is an open descriptor connected 
to a terminal and FALSE otherwise." clearly this is not the case. 
It also returns TRUE if the parameter is not a file descriptor at all except is 
it is an integer < 3.

Test script:
---------------
var_dump(posix_isatty(true));
var_dump(posix_isatty(false));
var_dump(posix_isatty('str'));
var_dump(posix_isatty(array()));
var_dump(posix_isatty(42));

for ($i=0; $i<50; $i++) {
    var_dump(posix_isatty($i));
}


Expected result:
----------------
(bool)false
(bool)false
(bool)false
(bool)false
(bool)false

(bool)false x50

Actual result:
--------------
(bool)true
(bool)true
(bool)true
(bool)true
(bool)false

(bool)true
(bool)true
(bool)true
(bool)false x47