php 生成32位随机字符串 用于支付验证 用户注册

 //32位随机字符串
function randstrpay($length=32) {
$rand='';
$randstr= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
$max = strlen($randstr)-1;
mt_srand((double)microtime()*1000000);
for($i=0;$i<$length;$i++) {
$rand.=$randstr[mt_rand(0,$max)];
}
return $rand;
}