MacOS – Does OS X Keep A Log Of Downloaded Files On My Mac

While I suspect that this is not what you want to do, you could always do something like schedule a maintenance task to run to limit the size of the file.

Something like this in a shell script that you schedule:

tail -n 10000 /var/log/DiagnosticMessages > /var/log/DiagnosticMessages

Or if you want to keep a history of the contents, something like this:

mv /var/log/DiagnosticMessages /var/log/DiagnosticMessages_$(date +%y%m%d)

If you want to get fancy, you could:

cat /var/log/DiagnosticMessages | wc -l

and then only rename the file if > 10K. As usual it all depends on how much effort you want to put into it, and whether or not you want a history of this file.

And as you said....this doesn't actually resolve the root cause.

I was able to pull up the logs on the router, but unfortunately they were only for current day. I would have needed to export the logs to have a chance to catch the guy. Oh well, it was worth a shot.

To do this, I needed to install the airport utility v5.6 (in addition to the v6.x that was already installed). The newer versions don't have an advanced tab which contains the ability to view "logs and statistics."