[Tracker] How to get newly added audio files?

[simon hong <simon hong81 gmail com>]

Dear Tracker folks,

I want to write small  program by using tracker.
(I want to use tracker because tracker can add new files automatically.)

That program loops infinitely, and gets newly added audio file list
from tracker.

At first loop, it gets all audio files from tracker.
And next loop (maybe some hours later), it fetches new files (if new
audio files are created or copied).

How can I get only new file list?

Any ideas (timestamp ?) will be appreciated.

Thank you.
Simon