Re: understanding how localization works in Debian

[Martin T <m4rtntns@gmail.com>]

On Mon, Dec 12, 2016 at 3:47 PM, Greg Wooledge <wooledg@eeg.ccf.org> wrote:
> On Mon, Dec 12, 2016 at 01:58:12PM +0200, Martin T wrote:
>> 1) pam_env.so sets the environmental variables seen in the output of
>> locale command based on configuration files(for example
>> /etc/default/locale) when user logs in
>
> Maybe, maybe not.  The LC_* and LANG variables can come from many
> different places.  I think, however, that you are focusing on the
> libc/application level that uses these variables, and not their
> origin.  So for your purposes, "LC_* and LANG are set somehow".
>
>> 2) nl_langinfo(), setlocale() and (some) other glibc functions used in
>> programs ask environment variables seen in the output of locale
>> command
>>
>> 3) based on those environment variables nl_langinfo(), setlocale(),
>> etc functions check the locale information in
>> /usr/lib/locale/locale-archive database and change their output
>> accordingly
>>
>> 4) /usr/lib/locale/locale-archive database is generated with
>> locale-gen utility based on entries in /etc/locale.gen file and locale
>> template/configuration files in /usr/share/i18n/locales/
>>
>> Did I understand this correctly?
>
> I am confused.  There are basically three interaction points between
> you and the locale system, and you don't seem to have focused on any
> of them.
>
> 1) LC_* and LANG are set somehow by the end user or by the local OS.
>
> 2) The local system admin runs "dpkg-reconfigure locales" to determine
>    which locales are "generated".  End users can only receive translations
>    from locales that are generated on the local system.
>
> 3) Applications are written with localization (l10n) support using the
>    features of whichever language they're written in, e.g. _("...").
>
> For a more detailed look at #1, see https://wiki.debian.org/Locale
> (And even that is woefully incomplete thanks to the proliferation
> of Desktop Environments, and the ridiculous inadequacy of the PAM
> environment variable system.)
>
> For a more detailed look at #3, see
> https://www.gnu.org/software/gettext/manual/gettext.html
>

Greg,

thank you for reply! I do understand that LC_* and LANG variables can
come from various places. For example even pushed by SSH client.
However, were my other three points incorrect? As I understand it,
some glibc functions(for example nl_langinfo(), setlocale()) use those
LC_* and LANG variables to change the program output(for example first
day of the week in cal command) based on locale data in
/usr/lib/locale/locale-archive database.



thanks,
Martin