PHP 小方法之 过滤参数

if (! function_exists ( 'parameter_filter' )) {
    function parameter_filter($str, $type = 'string', $filterhtml = 0) {
        $patterns [0] = "/script/";
        $replacements [0] = "";
        ksort ( $patterns );
        ksort ( $replacements );
        $str = preg_replace ( $patterns, $replacements, $str );
        $str = addslashes ( $str );
        switch ($type) {
            case "string" :
                break;
            case "number" :
                $str += 0;
                break;
            default :
                break;
        }
        
        if ($filterhtml == 0) {
            $pattern [0] = '/\&/';
            $pattern [1] = '/</';
            $pattern [2] = "/>/";
            $pattern [3] = '/\n/';
            $pattern [4] = '/"/';
            $pattern [5] = "/'/";
            $pattern [6] = "/%/";
            $pattern [7] = '/\(/';
            $pattern [8] = '/\)/';
            $pattern [9] = '/\+/';
            // $pattern[10] = '/-/';
            $replacement [0] = '&amp;';
            $replacement [1] = '&lt;';
            $replacement [2] = '&gt;';
            $replacement [3] = '<br>';
            $replacement [4] = '&quot;';
            $replacement [5] = '&#39;';
            $replacement [6] = '&#37;';
            $replacement [7] = '&#40;';
            $replacement [8] = '&#41;';
            $replacement [9] = '&#43;';
            // $replacement[10] = '&#45;';
            $str = preg_replace ( $pattern, $replacement, $str );
        }
        return $str;
    }