How to redirect NSLog to 3rd-party log destination in swift project?

Question

I have a project cite 3rd-party frameworks. in which it use NSLog. I'd like to redirect NSLog to other destination(say Dotzu)

Is it possible to override NSLog in my project?

Answer 1

You cannot overwrite it, because it is a function, not a method. However, NSLog() additionally writes to stderr under some conditions as stated in the discussion of NSLogv(), which is called by NSLog():

Logs an error message to the Apple System Log facility (see man 3 asl). If the STDERR_FILENO file descriptor has been redirected away from the default or is going to a tty, it will also be written there. If you want to direct output elsewhere, you need to use a custom logging facility.

So simply redirect STDERR_FILENO using freopen().