PHP版本不兼容

I have a PHP file with the following code:

<?php

// RECEIVE POST DATA

$xml = isset($HTTP_RAW_POST_DATA) ? $HTTP_RAW_POST_DATA : file_get_contents('php://input');

//  READ XML


$sxe = new SimpleXMLElement($xml);
..... rest codes here
?>

I was receiving xml data saved the $xml variable. Now I have a new server with PHP version 5.6.15 , I copied the same file that's worked during last three years, but now new version it doesn't work. I don't remember the old version that the file worked.

I have been told that some command was deprecated, how can I fix the problem? Thanks

$HTTP_RAW_POST_DATA is deprecated so you can not use it.

Try This instead:

$xml =  file_get_contents('php://input');