通过PHP将文件上传到SFTP服务器(phpseclib)

我不确定我做的是否正确,因为我之前没有处理过SFTP.这是我的代码的样子：

$file = "leads.csv";

$server = "41.160.150.200";
//$server = "ft.bayport.co.za";
$port = "22";
$username = "";
$password = ""; 

//username and password removed for security reasons

set_include_path(get_include_path() . PATH_SEPARATOR . 'phpseclib');

include 'Net/SFTP.php';

define('NET_SFTP_LOGGING',NET_SFTP_LOG_COMPLEX); // or NET_SFTP_LOG_SIMPLE

$sftp = new Net_SFTP($server);

// Check SFTP Connection
if (!$sftp->login($username,$password)) {
    echo 'Login Failed.';
    echo $sftp->getSFTPLog();
}else{

echo 'Connected to SFTP.';

echo $sftp->pwd();

// Upload CSVs to SFTP incoming folder
     echo $upload = $sftp->put("incoming/".$file,"./bayport/".$file,NET_SFTP_LOCAL_FILE);

}

我真的很感激任何帮助.谢谢！