I just implemented an instance of Mayan EDMS as a document manager. It's a destructive file manager. Everything added to the import folders are renamed to a unique identifier, file extension is stripped, it's copied to the app storage folder, and the original file in the import folder is deleted. 

 

Is there a way I can get every file added to the import folder immediately copied to a backup folder? I'd like it to happen as soon as it's added.   

Not exactly the same, but I used a find command that checks a folder and it copies from A to B and moves to C. 

find /mnt/cache/uploads/incoming/* -iname "*.mkv" -type f -mmin +10 -exec cp {} /mnt/cache/uploads/2check/ \; -exec mv {} /mnt/cache/uploads/Tv-Incoming/ \;
 

So it checks Incoming folder and copies to 2check then moves incoming to Tv-incoming

 

So this kinda does what your asking, but not exactly.  You could look for some code that utilizes inotifywait