PHP生成自定义长度随机字符串的函数分享

//随机生成字符串
function random($length) {
     srand(date("s"));
     $possible_charactors = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
     $string = "";
     while(strlen($string)<$length) {
          $string .= substr($possible_charactors,(rand()%(strlen($possible_charactors))),1);
     }
     return($string);
}