Write to a log file to get the HTTP origin of requests

log_origins.php

if (isset($_SERVER['HTTP_ORIGIN'])){
	$log_text = $_SERVER['HTTP_ORIGIN'];
}else{
	$log_text = 'UNKNOWN';
}
$filename = "./debug/origins.log";
$fh = fopen($filename, "a") or die("Could not open log file.");
fwrite($fh, date("d-m-Y, H:i")." - ".$log_text."\n") or die("Could not write file!");
fclose($fh);