Checking the file for integrity / loading after uploading via FTP?

Question

FTP

Good afternoon friends!
An interesting question has arisen.
There is an ftp server to which files are uploaded on a schedule.
The file is heavy and loads slowly.
Parsed after loading.
How to understand if the file has been downloaded completely or is still in the process of downloading?
There was an idea to do a file checksum every 10 seconds until it matches!

Answer 1

For decency, write at least what kind of OS and what FTP server.
For example, ProFTPd has a module that supports the execution of commands on a specific event. www.proftpd.org/docs/contrib/mod_exec.html