First are you acually trying to write anything to them ?
If you want the text to be specificly(sp?) written to the file stdout, use fprintf instead, as (correct me if im wrong here) printf is acually trying to write to the default data stream (or something like that) which is usually a command promt in windows, the compiler should be redrecting this to a file named stdout, but might not do this depending on your settings.
to write to the stdout with fprintf instead of printf:
fprintf(stdout, "your message here\n");
stdout is a simple predefined FILE struct (it is a struct isn't it?).
Edit: some tech errors