% arara: pdftex

\input tracklang

\TrackLangFromEnv % lookup LC_ALL or LANG
Environment query results:
language: \TrackLangEnvLang, 
territory: \TrackLangEnvTerritory,
codeset: \TrackLangEnvCodeSet,
modifier: \TrackLangEnvModifier.

\TrackPredefinedDialect{british}
\TrackPredefinedDialect{american}
\TrackPredefinedDialect{canadian}
\TrackPredefinedDialect{canadien}
\TrackPredefinedDialect{belgique}

\TrackLocale{de-NA@new}

\TrackLocale{manx}

Dialect Regions:

\ForEachTrackedDialect{\ThisDialect}{\ThisDialect:
 \TrackedIsoCodeFromLanguage{\TwoLetterIsoCountryCode}{\ThisDialect}%
 \IfHasTrackedDialectModifier\ThisDialect
 { (\GetTrackedDialectModifier\ThisDialect)}%
 {}.
}

Language Codes:

\ForEachTrackedLanguage{\ThisLanguage}{\ThisLanguage:
 \TrackedIsoCodeFromLanguage{\TwoLetterIsoLanguageCode}{\ThisLanguage}. }

\ForEachTrackedDialect{\ThisDialect}
{%
  \IfTrackedLanguageFileExists{\ThisDialect}{animals-}{.ldf}%
  {Found ``animals-\CurrentTrackedTag.ldf''\par}%
  {No file found for dialect ``\ThisDialect''\par}
}

\bye