You can use red_fm_io hook to track any i/o operations executed by users. These include create folder, create file, rename, duplicate, delete, paste, archive, extract, edit text file, search, use editor and resize image.
Here is an example usage:

function my_callback( $cmd, $result, $args, $elfinder, $volume ){
   //log user's last action
   update_option("user_last_operation", $cmd);
}
add_action( 'red_fm_io', 'my_callback', 10, 5 );