php生成随机密码的函数

function generatePassword($length=8)
{
    $chars = array_merge(range(0,9),
                   range('a','z'),
            range('A','Z'),
           array('!','@','$','%','^','&','*'));
    shuffle($chars);
    $password = '';
    for($i=0; $i<8; $i++) {
 $password .= $chars[$i];
    }
    return $password;
}