Just a short post to say that I asked about this on Stack Overflow and got a very nice answer from Ned Deily (here). He explains clearly what the different "executables" are about, and reminds me of a tool I'd overlooked:
otool. For example
Although it is not so helpful here:
I still think the
export DYLD_PRINT_LIBRARIES=1trick is pretty cool.
You can also look into
MachOView.appat Source Forge (here) and tried it. It gave me quite a bit of insight into the structure of our simple examples from the other day (here). The screenshot above is from a run on its own executable. There is very detailed info on the object code (or images in geek-speak).
I had been a bit worried about it since I can't find out anything about the guy (Peter Saghelyi). But I found the source, which is not under files. Do: