[tz] [PATCH 4/5] tzselect.ksh: time scales assumed

[Paul Eggert]

Christos Zoulas wrote:
> It would be good to stop using backquotes for command substitution
> at some point. We are requiring ksh for this script anyway...

The script does not require ksh; it tests dynamically for ksh extensions and 
uses them only if present. Also, the script uses backquotes for portability to 
Solaris /bin/sh. A comment in the script says:

# For portability to Solaris 9 /bin/sh this script avoids some POSIX
# features and common extensions, such as $(...) (which works sometimes
# but not others), $((...)), and $10.

The same problem occurs with Solaris 10 /bin/sh, which Oracle says they'll 
support until January 2021. Solaris 10 typically comes with other shells too, 
but we might as well continue to support /bin/sh if it's easy.

I think Solaris finally switched to a POSIX-compatible /bin/sh in Solaris 11.