[tz] rearguard

[Paul Eggert]

Brian Inglis wrote:
> Reminds me of limited AT&T/Sun SunOS/Solaris utilities doing this regularly.
> Saw this on Debian with a simple AWK script.
> Anyone tried BSD/BWK OTA (One True) awk?

Solaris 10 /usr/bin/awk (which is the closest to the original Awk implementation 
that I know of) definitely does not work with tzdb 2018e, as Solaris 10 awk 
lacks support for many POSIX features, starting with the -v option.

tzdb uses only awk features standardized by POSIX since 1992. At this point, a 
POSIX-1992-or-later awk should be available on every development platform of 
interest to tzdb, and it shouldn't be much trouble to ask developers to update 
to a 25-year-old standard or better. On Solaris 10, for example, you can use 
/usr/bin/nawk or /opt/sfw/bin/gawk (both shipped as part of Solaris 10). On 
Debian/Ubuntu/etc. you can use gawk.