php FTP文件:如何检查文件是否被另一个进程打开

I have a list of videos (.mp4) in a remote server. From my application codeigniter, I connect with FTP to the remote server and I can list those videos.
I want to rename those files, but I should verify if file is opened by another process (video is playing) before renaming it.
How can check if a file is opened by another process with php?

This my code:

$ftp = new Simple_ftp();
$ftp->init("server",'login','password');
$conn_id = $ftp->connexion();
if($conn_id == 3){
    $files = $ftp->ls('path_files');
    foreach($files as $file){
        ...
    }
}

You cannot check for that having only FTP access.

If the server is using Linux based OS and you have ssh access, you can remotely connect and use the lsof program.

There is no way of knowing by FTP, however other methods I suggest taking a look at the following: flock

It checks for file locking