Thought I'd also have a go at translating ch-1.pl and ch-2.c into C..

ch-1.c produces identical (non-debugging) output to my Perl original.

ch-1.c uses the command-line argument processing module args.[ch].

Ditto for ch-2.c.  Note that the C version (ch-2.c) is approx 12 times as
fast than my Perl version (ch-2.pl).