POSIX gettext() and the LANGUAGE environment variable

[Bruno Haible]

https://posix.rhansen.org/p/gettext_split
says (line 72)

  "For the LANGUAGE search, the value of the LANGUAGE environment
   variable shall be a list of one or more locale names separated
   by a colon (':') character."

This is NOT how GNU gettext behaves. If POSIX standardizes it like this,
GNU libc and GNU gettext will have the choice among
  (a) forcing users to specify their preferences in a user-unfriendly way, or
  (b) violating POSIX in this point.

I will vote for (b).

Namely, what gettext expects in the LANGUAGE environment variable is
documented in
https://www.gnu.org/software/gettext/manual/html_node/The-LANGUAGE-variable.html

In a modern glibc system, the locale names are essentially

  C
  POSIX
  en_US.UTF-8
  de_DE.UTF-8
  fr_FR.UTF-8
  pt_BR.UTF-8
  etc.

We do NOT want that user who wants to see messages in Arabic (1st preference)
or French (2nd preference) has to set

  LANGUAGE=ar_EG.UTF-8:fr_FR.UTF-8

We want that the user merely has to write

  LANGUAGE=ar:fr

Suggested wording change:

  "For the LANGUAGE search, the value of the LANGUAGE environment
   variable shall be a list of one or more language identifiers.
   A language identifier is a locale name with the '.codeset' part
   removed and optionally also the territory and/or the modifiers removed.
   In the simplest case, a language identifier consists of just an ISO 639-1
   code."

Bruno