需要在ssh会话中创建文件“ index.php”。

已使用：“ phpseclib / phpseclib”：“〜2.0”，

$ssh = new SSH2("192.168.138.5",22);
$ssh->login("user","mypass");
$ssh->write("cd /home/user/\n");
$ssh->read('[prompt]');

$ssh->exec("cat > index.php <<EOF
<?php
include($_SERVER['DOCUMENT_ROOT'] . '/header.php');
EOF\n");
$ssh->disconnect();
unset($ssh);

但是结果是：

<?php
include(['DOCUMENT_ROOT'] . '/header.php');

如何在ssh会话中将“ $ _SERVER”文本写入文件？