Description:
------------
the situation is that: 
run a php build in server, use commend: php -S 127.0.0.1:8081, and in you current 
dir, there are two file: a.php and b.php . a.php use file_get_contents catch a 
file:
<?php
echo file_get_contents('http://127.0.0.1:8081/b.php');
?>
b.php just  print string 'hello world'. When run the a.php through the web 
browser, you can find that, the build in server return 'failed to open stream: 
HTTP request failed!'.
If just browser the b.php, you can get hello world current, and if the file at 
a.php is not a http request which domain is the same of a.php, such as 'b.php', 
or 'http://google.com/', server is all right.
This kind problem do not occur when use apache as cgi.