Read message from console log?

I’m trying to write a script that will look in the console log for a specific message from the SheepShaver emulator. (The exact warning is: “WARNING: Unknown DiskStatus (6)”.) An older method described here no longer works:

I’ve been searching and can’t find exactly where these log files are stored under Leopard and later versions of OS X. Can anyone point me in the right direction? Many thanks for your help.

To answer my own question, the file is now: