AdminHelper::getRealPath

static function getRealPath($site, $url)
{
	$docRoot = rtrim(BitrixMainSiteTable::getDocumentRoot($site), '/');

	$url = str_replace('\', '/', $url);
	$url = CHTTP::urnEncode($url);
	$uri = new WebUri($url);

	$path = CHTTP::urnDecode($uri->getPath());
	if (mb_substr($path, -1, 1) == '/')
		$path .= 'index.php';

	$file = new IOFile($docRoot.$path);
	if ($file->isExists())
		return mb_substr($file->getPath(), mb_strlen($docRoot));

	if ($rewriteRules = AdminHelper::getRewriteRules($site))
	{
		$pathQuery = CHTTP::urnDecode($uri->getPathQuery());

		foreach ($rewriteRules as &$item)
		{
			if (preg_match($item['CONDITION'], $pathQuery))
			{
				$url = empty($item['PATH']) && !empty($item['RULE'])
					? preg_replace($item['CONDITION'], $item['RULE'], $pathQuery)
					: $item['PATH'];

				$url = CHTTP::urnEncode($url);
				$uri = new WebUri($url);

				$path = CHTTP::urnDecode($uri->getPath());

				$file = new IOFile($docRoot.$path);
				if ($file->isExists())
				{
					$pathTmp  = str_replace('.', '', mb_strtolower(ltrim($path, '/\')));
					$pathTmp7 = mb_substr($pathTmp, 0, 7);

					if ($pathTmp7 == 'upload/' || $pathTmp7 == 'bitrix/')
						continue;

					if ($file->getExtension() != 'php')
						continue;

					return mb_substr($file->getPath(), mb_strlen($docRoot));
				}
			}
		}
	}

	return null;
}