字符串过滤 , 截取替换敏感字符

/**
 * 字符串过滤 , 截取替换敏感字符
 * @ param  $string
 * @ return mixed
 */
function safe_replace($string) 
{
    if(empty($string)) { 
        return $string; 
    }
    $string = str_replace('%20','',$string);
    $string = str_replace('%27','',$string);
    $string = str_replace('%2527','',$string);
    $string = str_replace('*','',$string);
    $string = str_replace('"','"',$string);
    $string = str_replace("'",'',$string);
    $string = str_replace('"','',$string);
    $string = str_replace(';','',$string);
    $string = str_replace('<?','',$string);
    $string = str_replace('?>','',$string);
    $string = str_replace('script','',$string);
    $string = str_replace('<','',$string);
    $string = str_replace('>','',$string);
    $string = str_replace("{",'',$string);
    $string = str_replace('}','',$string);
    $string = str_replace('\\','',$string);
    return $string;
}