func.utilities.php

<?php

	/**
	 * @package boot
	 */

	/**
	 * Redirects the browser to a specified location. Safer than using a
	 * direct header() call
	 *
	 *	@param string $url
	 */
	function redirect ($url){
		// Just make sure.
		$url = str_replace('Location:', null, $url);

		if(headers_sent($filename, $line)){
			echo "<h1>Error: Cannot redirect to <a href=\"$url\">$url</a></h1><p>Output has already started in $filename on line $line</p>";
			exit;
		}

		header('Expires: Mon, 12 Dec 1982 06:00:00 GMT');
		header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT');
		header('Cache-Control: no-cache, must-revalidate, max-age=0');
		header('Pragma: no-cache');
		header("Location: $url");
		exit;
	}

	/**
	 * Returns the current working directory, replacing any \
	 *	with /. Use for Windows compatibility.
	 *
	 *	@return string
	 */
	function getcwd_safe(){
		return str_replace('\\', '/', getcwd());
	}

	/**
	 * Checks that a constant has not been defined before defining
	 * it. If the constant is already defined, this function will do
	 * nothing, otherwise, it will set the constant
	 *
	 * @param string $name
	 *	The name of the constant to set
	 * @param string $value
	 *	The value of the desired constant
	 */
	function define_safe($name, $value){
		if(!defined($name)) define($name, $value);
	}

	/**
	 * Returns the current URL string from within the Administration
	 * context. It omits the Symphony directory from the current URL.
	 *
	 *	@return string
	 */
	function getCurrentPage() {
		if(!isset($_GET['symphony-page'])) return null;

		return '/' . filter_var(trim($_GET['symphony-page'], '/'), FILTER_SANITIZE_STRING) . '/';
	}

	/**
	 * Used as a basic stopwatch for profiling. The default `$action`
	 * starts the timer. Setting `$action` to 'stop' and passing the
	 * start time returns the difference between now and that time.
	 *
	 *	@param string $action (optional)
	 *	@param integer $start_time (optional)
	 *	@return integer
	 */
	function precision_timer($action = 'start', $start_time = null){
		$currtime = microtime(true);

		if($action == 'stop')
			return $currtime - $start_time;

		return $currtime;
	}

	/**
	 * Convert php.ini size format to bytes
	 *
	 *	@param string $val (optional)
	 *	@return integer
	 */
	function ini_size_to_bytes($val) {
		$val = trim($val);
		$last = strtolower($val[strlen($val)-1]);

		switch($last) {
			case 'g':
				$val *= 1024;
			case 'm':
				$val *= 1024;
			case 'k':
				$val *= 1024;
		}

		return $val;
	}

	/**
	 * This function, give two DateTime objects, will return the
	 * difference between the two in hours and minutes, in a format
	 * suitable for MySQL.
	 *
	 * This function does not provide full date_diff functionality,
	 * it's a stopgap for PHP5.2 support.
	 *
	 * @since Symphony 2.3.3
	 * @deprecated Do not use, it will be removed in the next
	 *  major version of Symphony when PHP5.2 support is dropped
	 * @param DateTime $date_1
	 * @param DateTime $date_2
	 * @return string
	 *  A string representing the difference between the dates, eg.
	 *  +05:00 or -10:00 or +09:30
	 */
	function mysql_date_diff(DateTime $date_1, DateTime $date_2) {
		$date_1_seconds = $date_1->format('U');
		$date_2_seconds = $date_2->format('U');

		// In hours
		$offset = ($date_1_seconds - $date_2_seconds) / 60 / 60;

		// Deal with x.5 (:30 minutes)
		$minutes = (fmod($offset, 1) === 0.5) ? ":30" : ":00";

		// Is this +/- GMT?
		$op = ($offset > 0) ? '+' : '-';

		// Return difference, +05:00, -10:00, +09:30
		$difference = $op . str_pad(abs(floor($offset)), 2, '0', STR_PAD_LEFT) . $minutes;

		return $difference;
	}

	/**
	 * Cleans up Session Cookies. When there is no data in the session the cookie will be unset.
	 * If there is data, the cookie will be renewed, expiring it in two weeks from now.
	 * This will improve the interoperability with caches like Varnish and Squid.
	 *
	 * @since 2.3.3
	 * @author creativedutchmen (Huib Keemink)
	 * @return void
	 */
	function cleanup_session_cookies()
	{

		/*
		Unfortunately there is no way to delete a specific previously set cookie from PHP.
		The only way seems to be the method employed here: store all the cookie we need to keep, then delete every cookie and add the stored cookies again.
		Luckily we can just store the raw header and output them again, so we do not need to actively parse the header string.
		*/

		$cookie_params = session_get_cookie_params();
		$list = headers_list();
		$custom_cookies = array();

		foreach ($list as $hdr) {
			if ((stripos($hdr, 'Set-Cookie') !== FALSE) && (stripos($hdr, session_id()) === FALSE)) {
				$custom_cookies[] = $hdr;
			}
		}
		header_remove('Set-Cookie');
		foreach ($custom_cookies as $custom_cookie) {
			header($custom_cookie);
		}

		$session_is_empty = true;
		foreach ($_SESSION as $contents) {
			if (!empty($contents)) {
				$session_is_empty = false;
			}
		}
		if ($session_is_empty && !empty($_COOKIE[session_name()])) {
			setcookie(
				session_name(),
				session_id(),
				time() - 3600,
				$cookie_params['path'],
				$cookie_params['domain'],
				$cookie_params['secure'],
				$cookie_params['httponly']
			);
		}
		elseif(!$session_is_empty) {
			setcookie(
				session_name(),
				session_id(),
				time() + TWO_WEEKS,
				$cookie_params['path'],
				$cookie_params['domain'],
				$cookie_params['secure'],
				$cookie_params['httponly']
			);
		}
	}