So, I finally completed the first cut of my logger, and initially it was a LOT larger than the version in the repository, but after 'test driving', I found that (sadly) all my fancy ideas were just too fancy.
So, it's a pretty small 'opus', and just proves the rule that the shorter a piece of software is, the longer it takes to write.
I found that the ability to define new logging macros, set levels and display options, cherry pick levels to show and defining an output function on the fly really is more than enough for everything that is needed.
Other fails include that my idea to use 'ts -i "%.s"' from moreutils for adhoc profiling didn't really work properly for some reason that I cannot work out why.
If I try to use it with a macro that sets a few printout markers inside a function, all I get is that the expected function printf output stops totally whilst it does it's thing, then I get the total time taken put out on the top line, and everything that I expected to arrive 'peu-a-peu' comes in one go as it's finished doing the time wasting loop test, and it looks suspiciously like it's simply measuring the time it takes for writing to stdout via printf, and that some weird blockage is happening to the stdout output.
Oh well. Looks like I just have to write something else to have that service :-D