Locale::Util(3pm) User Contributed Perl Documentation Locale::Util(3pm)
NAME
Locale::Util - Portable l10n and i10n functions
SYNOPSIS
use Locale::Util;
my @linguas = parse_http_accept_language $ENV{HTTP_ACCEPT_LANGUAGE};
my @charsets = parse_http_accept_charset $ENV{HTTP_ACCEPT_CHARSET};
# Trie to set the locale to Brasilian Portuguese in UTF-8.
my $set_locale = set_locale LC_ALL, 'pt', 'BR', 'utf-8';
set_locale_cache $last_cache;
my $cache = get_locale_cache;
web_set_locale ($ENV{HTTP_ACCEPT_LANGUAGE}, $ENV_ACCEPT_CHARSET);
web_set_locale (['fr-BE', 'fr', 'it'], ['cp1252', 'utf-8']);
DESCRIPTION
This module provides portable functions dealing with localization
(l10n) and internationalization(i10n). It doesn't export anything by
default, you have to specify each function you need in the import list,
or use the fully qualified name.
The functions here have a focus on web development, although they are
general enough to have them in the Locale:: namespace.
This module is considered alpha code. The interface is not stable.
Please contact the author if you want to use it in production code.
This module was introduced in libintl-perl 1.17.
FUNCTIONS
parse_http_accept_language STRING
Parses a string as passed in the HTTP header "Accept-Language". It
returns a list of tokens sorted by the quality value, see RFC 2616
for details.
Example:
parse_http_accept ("fr-fr, fr; q=0.7, de; q=0.3");
This means: Give me French for France with a quality value of 1.0
(the maximum). Otherwise I will take any other French version
(quality 0.7), German has a quality of 0.3 for me.
The function will return a list of tokens in the order of their
quality values, in this case "fr-fr", "fr" and "de".
The function is more forgiving than RFC 2616. It accepts quality
values greater than 1.0 and with more than 3 decimal places. It
also accepts languages and country names with more than 8
characters. The language "*" is translated into "C".
parse_http_accept_charset STRING
Parses a string as passed in the HTTP header "Accept-Charset". It
returns a list of tokens sorted by the quality value, see RFC 2616
for details.
The special character set "*" (means all character sets) will be
translated to the undefined value.
set_locale CATEGORY, LANGUAGE[, COUNTRY, CHARSET]
Tries to set the user locale by means of POSIX::setlocale(). The
latter function has the disadvantage, that its second argument (the
locale description string) is completely non-standard and system-
dependent. This function tries its best at guessing the system's
notion of a locale dientifier, with the arguments supplied:
CATEGORY
An integer argument for a valid locale category. These are
the LC_* constants (LC_ALL, LC_CTIME, LC_COLLATE, ...)
defined in both Locale::Messages(3pm) and POSIX(3pm).
LANGUAGE
A 2-letter language identifier as per ISO 639. Case
doesn't matter, but an unchanged version (ie. not lower-
cased) of the language you provided will always be tried
to.
COUNTRY A 2-letter language identifier as per ISO 639. Case
doesn't matter, but an unchanged version (ie. not lower-
cased) of the language you provided will always be tried
to.
This parameter is optional. If it is not defined, the
function will try to guess an appropriate country,
otherwise leave it to the operating system.
CHARSET A valid charset name. Valid means valid! The charset
"utf8" is not valid (it is "utf-8"). Charset names that
are accepted by the guessing algorithms in Encode(3pm) are
also not necessarily valid.
If the parameter is undefined, it is ignored. It is always
ignored under Windows.
The function tries to approach the desired locale in loops,
refining it on every success. It will first try to set the
language (for any country), then try to select the correct
language, and finally try to select the correct charset.
The return value is false in case of failure, or the return value
of the underlying POSIX::setlocale() call in case of success.
In array context, the function returns the country name that was
passed in the successful call to POSIX::setlocale(). If this
string is equal to the country name you passed as an argument, you
can be reasonably sure that the settings for this country are
really used. If it is not equal, the function has taken a guess at
the country (it has a list of "default" countries for each
language). It seems that under Windows, POSIX::setlocale() also
succeeds, if you pass a country name that is actually not
supported. Therefore, the information is not completely reliable.
Please note that this function is intended for server processes
(especially web applications) that need to switch in a portable way
to a certain locale. It is not the recommended way to set the
program locale for a regular application. In a regular application
you should do the following:
use POSIX qw (setlocale LC_ALL);
setlocale LC_ALL, '';
The empty string as the second argument means, that the system
should switch to the user's default locale.
get_locale_cache
The function set_locale() is potentially expansive, especially when
it fails, because it can try a lot of different combinations, and
the system may have to load a lot of locale definitions from its
internal database.
In order to speed up things, results are internally cached in a
hash, keys are the languages, subkeys countries, subsubkeys the
charsets. You can get a reference to this hash with
get_locale_cache().
The function cannot fail.
set_locale_cache HASH
Sets the internal cache. You can either pass a hash or a hash
reference. The function will use this as its cache, discarding its
old cache. This allows you to keep the hash persistent.
The function cannot fail.
web_set_locale (ACCEPT_LANGUAGE, ACCEPT_CHARSET, CATEGORY, AVAILABLE)
Try to change the locale to the settings described by
ACCEPT_LANGUAGE and ACCEPT_CHARSET. For each argument you can
either pass a string as in the corresponding http header, or a
reference to an array of language resp. charset identifiers.
Currently only the first charset passed is used as an argument.
You are strongly encouraged to pass a hard-coded value here, so
that you have control about your output.
The argument CATEGORY specifies the category (one of the LC_*
constants as defined in Locale::Messages(3pm) or in POSIX(3pm)).
The category defaults to LC_ALL.
You can pass an optional reference to a list of locales in XPG4
format that are available in your application. This is useful if
you know which languages are supported by your application. In
fact, only the language part of the values in the list are
considered (for example for "en_US", only "en" is used). The
country or other parts are ignored.
The function returns the return value of the underlying
set_locale() call, or false on failure.
The function returns false on failure. On success it returns the
return value of the underlying set_locale() call. This value can
be used directly in subsequent calls to POSIX::setlocale(). In
array context, it additionally returns the identifiers for the
language, the country, and the charset actually used.
BUGS
The function set_locale() probably fails to guess the correct locale
identifier on a lot of systems. If you have found such a case, please
submit it as a bug report.
The bug tracking system for this packags is at
http://rt.cpan.org/NoAuth/Bugs.html?libintl-perl
Please note that this module is considered alpha code, and the
interface is not stable. Please contact the author, if you want to use
it in production code.
AUTHOR
Copyright (C) 2002-2017 Guido Flohr <http://www.guido-flohr.net/>
(<mailto:guido.flohr@cantanea.com>), all rights reserved. See the
source code for details!code for details!
SEE ALSO
POSIX(3pm), perl(1)
perl v5.36.0 2022-12-22 Locale::Util(3pm)
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