[tz] Version in zoneinfo files?

[Paul Eggert]

John Hawkinson wrote:
> the idea is to have the string displayable using a semi-standard tool.

On GNU/Linux a common tool for that is the 'file' command. For example, on 
Fedora 25:

$ file /usr/share/zoneinfo/America/Los_Angeles
/usr/share/zoneinfo/America/Los_Angeles: timezone data, version 2, 5 gmt time 
flags, 5 std time flags, no leap seconds, 186 transition times, 5 abbreviation chars

Here the string "America/Los_Angeles" is already part of the output. Presumably 
the intended application for a change to the binary file format is when the 
binary file has been renamed or linked and someone wants to know the 
"originally-intended" or "canonical" name. tz follows the Unix tradition where 
files do not have canonical names - a design flaw to some, and a design feature 
to others.