In this code snippet, $Call_is_from and $Recording match the Twilio call log, but $Duration is much to small to be the # seconds of the completed call:
<?php
require_once 'log_file.php';
$Recording = $_REQUEST['RecordingUrl'];
$Call_is_from = $_REQUEST['Call_from'];
$Duration = $_REQUEST['Duration'];
log_msg("$Call_is_from\t$Duration\t$Recording");
?>