Serve JSONP in php

serve-jsonp.php

<?php
	header('Content-type: application/javascript; charset=utf-8');
	
	function getJSON($path)
	{
		return file_get_contents($path);
	}
	
	function getJSONP($path, $callback)
	{
		return sprintf("%s(%s);", $callback, getJSON($path));
	}
	
	if (!isset($_SERVER['PATH_TRANSLATED']))
	{
		// Attempting to call this file manually
		header('HTTP/1.1 404 Not Found');
	}
	
	$path = $_SERVER['PATH_TRANSLATED'];
	
	// Check for a malicious attempt to read a non-JSON file
	if (!preg_match('/\.json$/i', $path))
	{
		header('HTTP/1.1 404 Not Found');
		die();
	}
	
	// Check for a malicious attempt to read outside the document root
	$documentRoot = str_replace('/', '\\/', $_SERVER['DOCUMENT_ROOT']);
	$documentRegex = sprintf('/^%s/', $documentRoot);
	if (!preg_match($documentRegex, $path))
	{
		header('HTTP/1.1 404 Not Found');
		die();
	}
	
	// Make sure the file exists
	if (!is_file($path))
	{
		header('HTTP/1.1 404 Not Found');
		die();
	}
	
	if (isset($_GET['callback']))
	{
		// Serving JSONP (JSON+callback)
		$data = getJSONP($path, $_GET['callback']);
	}
	else
	{
		// Serving JSON
		$data = getJSON($path);
	}
	
	echo $data;
	die();
?>