log php backtrace to a file

dmdbt.php

<?php
$dmdbtf = fopen('/home/meeuw/log.txt', 'w');
function dmdbt($bt) {
	global $dmdbtf;
	if (isset($bt[0]['class']) && isset($bt[1]['class'])) {
		fwrite($dmdbtf, "\"{$bt[1]['class']} {$bt[1]['function']}\" -> ".
			"\"{$bt[0]['class']} {$bt[0]['function']}\"\n"
		);
		fflush($dmdbtf);
	}
}