At the same time as WG14 (the C committee) voted C23, now all 21 sections of the new edition are available via Manning’s early access program on
Modern C, Third Edition — Covers the C23 standard
This new edition broadly covers all the novelties that will come with C23, many of them make coding in C easier and more reliable. It’s worth a look. Major public domain compilers such as gcc and clang are getting ready to support most of this in their next releases, so you on many platforms you will be able to use these new features right away.
Some pieces are still missing though, namely some of the C library support. Therefor the part in the appendix for C23 about just that is not yet ready, but we will be getting there soon.
You might be interested in the special code that you can get on
and the previous post that described the whole
Jens Gustedt's Blog 