On Jan 10, 2020, at 10:26 PM, enh via tz <tz@iana.org> wrote:
NetBSD already supported regular expressions in RS, and they upstreamed that to one-true-awk last year
macOS: https://opensource.apple.com/source/awk/awk-24/ uses what I'm guessing, based on the Lucent copyrights, is the One True Awk: https://github.com/onetrueawk/awk and I suspect most if not all of the *BSDs do so as well, but macOS seems to be using a 2007-vintage version. Perhaps they should update, especially to a version that has...
(https://github.com/onetrueawk/awk/commit/643a5a3dad633431c6ce8831944c23059a6... and https://github.com/onetrueawk/awk/commit/7cae39dfa53e17981990f649a2f6b4c1ba8...) so hopefully all the OSes not using gawk can unify at some point.
...that change.
but, yeah, right now most awks don't have this ability.
...so the tzcode should probably not depend on it.