Thought I'd also have a go at translating ch-1.pl into C..

Of course, it can only deal with lists of integers, so the original
examples have to change.

It produce identical (non-debugging) output to my Perl original.

It uses several of my regular support modules:
- a command-line argument processing module args.[ch],
- a csvlist-of-int parsing module parseints.[ch], and
- an int-array printing module printarray.[ch].