生成随机的imei

<?php
echo getIMEI();

function getIMEI() {// calculator IMEI  
    $r1=1000000+rand(0,8999999);
    $r2=1000000+rand(0,8999999);
    $input=$r1.$r2;
    $a=$b=0;
    for($i=0;$i<strlen($input);$i++){
        $tt=intval($input[$i]);
        if ($i % 2 == 0) {  
            $a=$a+$tt;  
        } else {  
            $temp = $tt * 2;  
            $b = $b + $temp / 10 + $temp % 10;  
        } 
    }
    $last = ($a + $b) % 10;  
    if ($last == 0) {  
        $last = 0;  
    } else {  
        $last = 10 - $last;  
    }  
    return $input.$last;
}

?>