Many programming languages have some sort of file-to-hash function built in. PHP has md5_file(), python has hashlib.md5(), etc. I believe the easiest way to ac

Many programming languages have some sort of file-to-hash function built in. PHP has md5_file(), python has hashlib.md5(), etc. I believe the easiest way to accomplish your goal is to get the md5 hash of the file before and after and compare the two results.