cron作业不会写入文件

Question

我运行一个Windows 2003服务器,并尝试每15分钟运行一次这样的代码:

require("db_connect.php");
$conn = db_connect();

//list online brukere - flytt funksjon til separat side for bedre ytelse
$time = time() - 900;
$query ="SELECT username FROM tbl_user WHERE last_online >= $time";
$online_users; 
if ($result = $conn->query($query)) {
    while ($row = $result->fetch_assoc()) {
        $online_users .= $row["username"].":";
    }
    $result->close();
}   

$filename = "online_users.txt";
$fp = fopen($filename,"w");
fputs($fp,$online_users);
fclose($fp);

当我转到url或从命令行运行它时它会工作并写入文件.但任务只是运行而不保存文件..出了什么问题？

Answer 1

$filename = dirname(__FILE__) . "/online_users.txt";