Minify_CSS_UriRewriter::_processUriCB PHP Method

    private static function _processUriCB($m)
    {
        // $m matched either '/@import\\s+([\'"])(.*?)[\'"]/' or '/url\\(\\s*([^\\)\\s]+)\\s*\\)/'
        $isImport = $m[0][0] === '@';
        // determine URI and the quote character (if any)
        if ($isImport) {
            $quoteChar = $m[1];
            $uri = $m[2];
        } else {
            // $m[1] is either quoted or not
            $quoteChar = $m[1][0] === "'" || $m[1][0] === '"' ? $m[1][0] : '';
            $uri = $quoteChar === '' ? $m[1] : substr($m[1], 1, strlen($m[1]) - 2);
        }
        // if not root/scheme relative and not starts with scheme
        if (!preg_match('~^(/|[a-z]+\\:)~', $uri)) {
            // URI is file-relative: rewrite depending on options
            if (self::$_prependPath === null) {
                $uri = self::rewriteRelative($uri, self::$_currentDir, self::$_docRoot, self::$_symlinks);
            } else {
                $uri = self::$_prependPath . $uri;
                if ($uri[0] === '/') {
                    $root = '';
                    $rootRelative = $uri;
                    $uri = $root . self::removeDots($rootRelative);
                } elseif (preg_match('@^((https?\\:)?//([^/]+))/@', $uri, $m) && false !== strpos($m[3], '.')) {
                    $root = $m[1];
                    $rootRelative = substr($uri, strlen($root));
                    $uri = $root . self::removeDots($rootRelative);
                }
            }
        }
        if ($isImport) {
            return "@import {$quoteChar}{$uri}{$quoteChar}";
        } else {
            return "url({$quoteChar}{$uri}{$quoteChar})";
        }
    }