Locale – Difference Between LANG=C and LC_ALL=C

locale

I like to disable all locale specific differences in shell scripts. What is the preferred way to do it?

LANG=C or LC_ALL=C

Best Answer

LANG sets the default locale, i.e. the locale used when no more specific setting (LC_COLLATE, LC_NUMERIC, LC_TIME etc.) is provided; it doesn’t override any setting, it provides the base value. LC_ALL on the other hand overrides all locale settings.

Thus to override scripts’ settings, you should set LC_ALL.

You can check the effects of your settings by running locale. It shows the calculated values, in quotes, for all locale categories which aren’t explicitly set; in your example, LANG isn’t overriding LC_NUMERIC, it’s providing the default value. If LC_ALL and LC_NUMERIC aren’t set in the environment, the locale is taken from LANG, and locale shows that value for LC_NUMERIC, as indicated by the quotes.

See the locales manpage and the POSIX definitions of environment variables for details. See also How does the "locale" program work?

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Linux – Why does locale es_MX work but not es

Wikipedia is probably not the best reference for stuff like this. It usually has very simple examples that may not be widely applicable, constructed for understanding concepts more than for practical considerations.

Why not use gnu's own documentation?

http://www.gnu.org/software/gettext/manual/gettext.html#Setting-the-POSIX-Locale

You can set LANGUAGE to "es" (or even "es:fr:en" for a priority list), but LANG would still need to be set to es_MX or something like that. The docs explain it fairly clearly.

How to change locale environment variable

You can set any locale category independently. LANG applies only to the categories that are not explicitly set.

LANG and LC_xxx are ordinary environment variables. They are not settings for the locale utility: the locale program isn't involved in any locale processing, it's just a small utility to report current and available locale settings.

When you write LC_TIME=ru_RU.utf8, this doesn't set an environment variable, only a shell variable. Shell variables are internal to the shell, they are not seen by other programs. Environment variables, on the other hand, are inherited by the programs that the shell starts. You need to export the variable to the environment as well:

$ LC_TIME=ru_RU.utf8
$ locale | grep LC_TIME
LC_TIME="et_EE.iso88591"
$ export LC_TIME
$ locale | grep LC_TIME
LC_TIME="ru_RU.utf8"

or directly

$ export LC_TIME=ru_RU.utf8
$ locale | grep LC_TIME
LC_TIME="ru_RU.utf8"

Best Answer

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