通过SSH获取CPU使用率

我想通过SSH检索CPU利用率百分比,我尝试了命令"top",但它不会让我.

我正在使用CentOS 6.

我试过这段代码

$connection = ssh2_connect("IP", PORT);
ssh2_auth_password($connection, "root", "PASS");
$stream = ssh2_exec($connection, "top");
$errorStream = ssh2_fetch_stream($stream, SSH2_STREAM_STDERR);

// Enable blocking for both streams
stream_set_blocking($errorStream, true);
stream_set_blocking($stream, true);

// Whichever of the two below commands is listed first will receive its appropriate output.  The second command receives nothing
echo "Output: " . stream_get_contents($stream);
echo "Error: " . stream_get_contents($errorStream);

// Close the streams        
fclose($errorStream);
fclose($stream);

但它每次都给我一个错误:输出:错误:未设置TERM环境变量.

我正在使用PHP.