I18N::LangTags::Detect - detect the user's language preferences

Sean M. Burke "sburke@cpan.org" perl v5.40.1 2025-07-03 I18N::LangTags::Detect(3perl)

Copyright (c) 1998-2004 Sean M. Burke. All rights reserved. This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The programs and documentation in this dist are distributed in the hope that they will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose.

It is a common problem to want to detect what language(s) the user would prefer output in.

This module looks at several environment variables: REQUEST_METHOD, HTTP_ACCEPT_LANGUAGE, LANGUAGE, LC_ALL, LC_MESSAGES, and LANG. It will also use the Win32::Locale module, if it's installed and IGNORE_WIN32_LOCALE is not set to a true value in the environment.

This module defines one public function, I18N::LangTags::Detect::detect(). This function is not exported (nor is even exportable), and it takes no parameters. In scalar context, the function returns the most preferred language tag (or undef if no preference was seen). In list context (which is usually what you want), the function returns a (possibly empty) list of language tags representing (best first) what languages the user apparently would accept output in. You will probably want to pass the output of this through I18N::LangTags::implicate_supers_tightly(...) or I18N::LangTags::implicate_supers(...), like so: my @languages = I18N::LangTags::implicate_supers_tightly( I18N::LangTags::Detect::detect() );

I18N::LangTags::Detect - detect the user's language preferences

I18N::LangTags, Win32::Locale, Locale::Maketext. (This module's core code started out as a routine in Locale::Maketext; but I moved it here once I realized it was more generally useful.)

use I18N::LangTags::Detect; my @user_wants = I18N::LangTags::Detect::detect();