通过PHP

Question

我有两个服务器，

• A：webserver
• B：DNS服务器

我有以下代码，我放入服务器A，

<?php $submit = $_POST['submit'];
if($submit == "Restart") {
if (!function_exists("ssh2_connect")) die("function ssh2_connect doesn't
exist");
if(!($con = ssh2_connect("x.x.x.x", 22))){
echo "fail: unable to establish connection\n";
} else {
if(!ssh2_auth_password($con, "user", "password")) {
    echo "fail: unable to authenticate\n";
} else {
    // allright, we're in!
    echo "OK: logged in...end Restart\n";

    // execute a command
    if (!($stream = ssh2_exec($con, "service bind9 restart" ))) {
        echo "fail: unable to execute command\n";
    } else {
        // collect returning data from command
        stream_set_blocking($stream, true);
        $data = "";
        while ($buf = fread($stream,4096)) {
            $data .= $buf;
        }
        fclose($stream);
        echo "<pre>";
        echo $data; //Prints the output
        echo "</pre>"; 
        } 
      } 
    } 
  } echo '<form action="" method="post"
    <input type="submit" name="submit" value="Restart"></form>';
  ?>

问题是，当我从服务器A执行代码时， 服务器B不想重启。 但是，当我改变代码命令，如＆＃34; dmesg，ifconfig，whoami＆＃34;代码是工作，我只想重启服务bind9 我们可以做这个模拟.. 谢谢你的帮助