具体来说，如何获取用户的所有文件？

Using the built-in concrete5 file manager, how can I get a user's files (by the user's ID or otherwise)?

I'm looking for something like this:

$user_id = 123;
$FileList = new FileList();
$FileList->filterByUserId($user_id);

Edit: I understand this question is very basic, but I posted it hoping to help others out because I did not see an answer on SO. If I've made any mistakes in my question, please let me know how I can improve.

You can achieve this using the \Concrete\Core\File\FileList class:

<?php
$user_id = 111;

$list = new \Concrete\Core\File\FileList();
$list->filterByAuthorUserID($user_id);

$files = $list->executeGetResults();