randVerify.php

/**
  * 生成随机验证码
  * @param integer $codeLenth：随机验证码长度
  * @param string $onlyNumber：默认为只获取数字
  * @return number
  */
 function randVerify($codeLenth,$onlyNumber=TRUE)
 {
     if ($onlyNumber == TRUE){
         $code = '';
         for($i = 1 ; $i <=$codeLenth ; $i++){
             $code .= rand(0,9);
         }
         return $code;
     }
     $chars='ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz';
     $string=time();
     $len = 11;
     for(;$len>=1;$len--)
     {
         $position=rand()%strlen($chars);
         $position2=rand()%strlen($string);
         $string=substr_replace($string,substr($chars,$position,1),$position2,0);
     }
     return substr($string, 0 , $codeLenth);
 }