G'day fefofe,

Welcome to the Monastery.

"A setting off 600 leads to this: ---x-wx--T I'm really confused about this"

Firstly, 600 decimal is 1130 octal:

$ perl -E 'say 01130'
600
[download]

The permissions you show are correct for that number:

$ > fred
$ ls -l fred
-rw-r--r-- 1 ken staff 0 Sep 16 14:16 fred
$ chmod 1130 fred
$ ls -l fred
---x-wx--T 1 ken staff 0 Sep 16 14:16 fred
[download]

You don't show how you're using "600"; regardless, it's clearly being read as a decimal number, as indicated by "---x-wx--T".

If you replace "600" with "384", as shown by choroba, that should give you the wanted permissions of "-rw-------".

Perhaps also look at "umask" in the OPTIONS section of Log::Log4perl::Appender::File.