get_custom_logo.php

<?php
/************************************************************************/
/* ATutor																*/
/************************************************************************/
/* Copyright (c) 2002-2010                                              */
/* Inclusive Design Institute                                           */
/* http://atutor.ca                                                     */
/* This program is free software. You can redistribute it and/or        */
/* modify it under the terms of the GNU General Public License          */
/* as published by the Free Software Foundation.                        */
/************************************************************************/

define('AT_INCLUDE_PATH', 'include/');

@ob_end_clean();
header("Content-Encoding: none");

$_user_location	= 'public';

require(AT_INCLUDE_PATH . 'vitals.inc.php');
require(AT_INCLUDE_PATH . 'lib/mime.inc.php');

$file = AT_CONTENT_DIR .'/logos/custom_logo.';

// The following line fails, returning an error
// substr() expects parameter 1 to be string, array given in /var/www/ATutor/get_custom_logo.php on line 24
//$ext = substr(glob($file.'{jpg,png,gif}', GLOB_BRACE), -3, 4);

// So a hack to figure out the file extention
if(file_exists($file."png")){
    $ext = "png";
} else if(file_exists($file."gif")){
    $ext = "gif";
} else if(file_exists($file."jpg")){
    $ext = "jpg";
}


$file = $file.$ext;

$real = realpath($file);

if (file_exists($real) && (substr($real, 0, strlen(AT_CONTENT_DIR)) == AT_CONTENT_DIR)) {

	header('Content-Disposition: inline; filename="custom_logo.'.$ext.'"');
	
	/**
	 * although we can check if mod_xsendfile is installed in apache2
	 * we can't actually check if it's enabled. also, we can't check if
	 * it's enabled and installed in lighty, so instead we send the 
	 * header anyway, if it works then the line after it will not
	 * execute. if it doesn't work, then the line after it will replace
	 * it so that the full server path is not exposed.
	 *
	 * x-sendfile is supported in apache2 and lighttpd 1.5+ (previously
	 * named x-send-file in lighttpd 1.4)
	 */
	header('x-Sendfile: '.$real);
	header('x-Sendfile: ', TRUE); // if we get here then it didn't work

	header('Content-Type: '.$ext);

	@readfile($real);
	exit;
} else {
	header('HTTP/1.1 404 Not Found', TRUE);
	exit;
}

?>