获取随机字符串

 1 /**
 2  * 获取随机字符串
 3  * @param int $randLength 长度
 4  * @param int $addtime 是否加入时间戳
 5  * @param int $format 0:只字符 1:字符和数字 2:只数字
 6  * @return string
 7  */
 8 function getRandStr($randLength=6, $addtime=1, $format=0){
 9     switch($format){
10         case '0':
11             $chars='abcdefghijklmnopqrstuvwxyz';
12             break;
13         case '1':
14             $chars='abcdefghijklmnopqrstuvwxyzABCDEFGHJKLMNPQEST123456789';
15             break;
16         case '2':
17             $chars='0123456789';
18             break;
19         default :
20             $chars='abcdefghijklmnopqrstuvwxyzABCDEFGHJKLMNPQEST123456789';
21             break;
22     }
23     $len=strlen($chars);
24     $randStr='';
25     for ($i=0;$i<$randLength;$i++){
26         $randStr.=$chars[rand(0,$len-1)];
27     }
28     $tokenvalue=$randStr;
29     if ($addtime){
30         $tokenvalue=time().$randStr;
31     }
32     return $tokenvalue;
33 }