monitor changes in a file or directory?

Question

In Android, how do I monitor changes made by others (app, internet, bluetooth, dll) to a file or directory

Answer 1

No, in standard android, you don't monitor for activities of others, app, internet etc.

Your program can only track and access your data directory. Others uses its own directories.

But, if you have rooted a telephone, you can write/start a root process or suid process. But this solution is only valid for rooted telephones..