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/ I18N::Langinfo

NAME

I18N::Langinfo - query locale information

SYNOPSIS

  use I18N::Langinfo;

DESCRIPTION

The langinfo() function queries various locale information that can be used to localize output and user interfaces. It uses the current underlying locale, regardless of whether or not it was called from within the scope of use locale. The langinfo() function requires one numeric argument that identifies the locale constant to query: if no argument is supplied, $_ is used. The numeric constants appropriate to be used as arguments are exportable from I18N::Langinfo.

The following example will import the langinfo() function itself and three constants to be used as arguments to langinfo(): a constant for the abbreviated first day of the week (the numbering starts from Sunday = 1) and two more constants for the affirmative and negative answers for a yes/no question in the current locale.

    use I18N::Langinfo qw(langinfo ABDAY_1 YESSTR NOSTR);

    my ($abday_1, $yesstr, $nostr) =
        map { langinfo($_) } (ABDAY_1, YESSTR, NOSTR);

    print "$abday_1? [$yesstr/$nostr] ";

In other words, in the "C" (or English) locale the above will probably print something like:

    Sun? [yes/no]

but under a French locale

    dim? [oui/non]

The usually available constants are as follows.

  • For abbreviated and full length days of the week and months of the year:

        ABDAY_1 ABDAY_2 ABDAY_3 ABDAY_4 ABDAY_5 ABDAY_6 ABDAY_7
    ABMON_1 ABMON_2 ABMON_3 ABMON_4 ABMON_5 ABMON_6
    ABMON_7 ABMON_8 ABMON_9 ABMON_10 ABMON_11 ABMON_12
    DAY_1 DAY_2 DAY_3 DAY_4 DAY_5 DAY_6 DAY_7
    MON_1 MON_2 MON_3 MON_4 MON_5 MON_6
    MON_7 MON_8 MON_9 MON_10 MON_11 MON_12

  • For the date-time, date, and time formats used by the strftime() function (see POSIX):

        D_T_FMT D_FMT T_FMT

  • For the locales for which it makes sense to have ante meridiem and post meridiem time formats:

        AM_STR PM_STR T_FMT_AMPM

  • For the character code set being used (such as "ISO8859-1", "cp850", "koi8-r", "sjis", "utf8", etc.):

        CODESET

  • For the symbol or string of characters that indicates a number is a monetary value:

        CRNCYSTR

    An example is the dollar sign $. Some locales not associated with particular locations may have an empty currency string. (The C locale is one.) Otherwise, the return of this is always prefixed by one of these three characters:

    -

    indicates that in this locale, the string precedes the numeric value, as in a U.S. locale: $9.95.

    +

    indicates that in this locale, the string follows the numeric value, like 9.95USD.

    .

    indicates that in this locale, the string replaces the radix character, like 9$95.

  • For an alternate representation of digits, for the radix character used between the integer and the fractional part of decimal numbers, the group separator string for large-ish floating point numbers (yes, the final two are redundant with POSIX::localeconv()):

        ALT_DIGITS RADIXCHAR THOUSEP

  • For the affirmative and negative responses and expressions:

        YESSTR YESEXPR NOSTR NOEXPR

  • For the eras based on typically some ruler, such as the Japanese Emperor (naturally only defined in the appropriate locales):

        ERA ERA_D_FMT ERA_D_T_FMT ERA_T_FMT

In addition, Linux boxes have extra items, as follows. (When called from other platform types, these return a stub value, of not much use.)

_NL_ADDRESS_POSTAL_FMT
_NL_ADDRESS_COUNTRY_NAME
_NL_ADDRESS_COUNTRY_POST
_NL_ADDRESS_COUNTRY_AB2
_NL_ADDRESS_COUNTRY_AB3
_NL_ADDRESS_COUNTRY_CAR
_NL_ADDRESS_COUNTRY_NUM
_NL_ADDRESS_COUNTRY_ISBN
_NL_ADDRESS_LANG_NAME
_NL_ADDRESS_LANG_AB
_NL_ADDRESS_LANG_TERM
_NL_ADDRESS_LANG_LIB

On Linux boxes, these return information about the country for the current locale. Further information is found in langinfo.h

_NL_IDENTIFICATION_TITLE
_NL_IDENTIFICATION_SOURCE
_NL_IDENTIFICATION_ADDRESS
_NL_IDENTIFICATION_CONTACT
_NL_IDENTIFICATION_EMAIL
_NL_IDENTIFICATION_TEL
_NL_IDENTIFICATION_FAX
_NL_IDENTIFICATION_LANGUAGE
_NL_IDENTIFICATION_TERRITORY
_NL_IDENTIFICATION_AUDIENCE
_NL_IDENTIFICATION_APPLICATION
_NL_IDENTIFICATION_ABBREVIATION
_NL_IDENTIFICATION_REVISION
_NL_IDENTIFICATION_DATE
_NL_IDENTIFICATION_CATEGORY

On Linux boxes, these return meta information about the current locale, such as how to get in touch with its maintainers. Further information is found in langinfo.h

_NL_MEASUREMENT_MEASUREMENT

On Linux boxes, it returns 1 if the metric system of measurement prevails in the locale; or 2 if US customary units prevail.

_NL_NAME_NAME_FMT
_NL_NAME_NAME_GEN
_NL_NAME_NAME_MR
_NL_NAME_NAME_MRS
_NL_NAME_NAME_MISS
_NL_NAME_NAME_MS

On Linux boxes, these return information about how names are formatted and the personal salutations used in the current locale. Further information is found in locale(7) and langinfo.h

_NL_PAPER_HEIGHT
_NL_PAPER_WIDTH

On Linux boxes, these return the standard size of sheets of paper (in millimeters) in the current locale.

_NL_TELEPHONE_TEL_INT_FMT
_NL_TELEPHONE_TEL_DOM_FMT
_NL_TELEPHONE_INT_SELECT
_NL_TELEPHONE_INT_PREFIX

On Linux boxes, these return information about how telephone numbers are formatted (both domestically and international calling) in the current locale. Further information is found in langinfo.h

For systems without nl_langinfo

This module originally was just a wrapper for the libc nl_langinfo function, and did not work on systems lacking it, such as Windows.

Starting in Perl 5.28, this module works on all platforms. When nl_langinfo is not available, it uses various methods to construct what that function, if present, would return. But there are potential glitches. These are the items that could be different:

ERA

Unimplemented, so returns "".

CODESET

This should work properly for Windows platforms. On almost all other modern platforms, it will reliably return "UTF-8" if that is the code set. Otherwise, it depends on the locale's name. If that is of the form foo.bar, it will assume bar is the code set; and it also knows about the two locales "C" and "POSIX". If none of those apply it returns "".

YESEXPR
YESSTR
NOEXPR
NOSTR

Only the values for English are returned. YESSTR and NOSTR have been removed from POSIX 2008, and are retained here for backwards compatibility. Your platform's nl_langinfo may not support them.

D_FMT

Always evaluates to %x, the locale's appropriate date representation.

T_FMT

Always evaluates to %X, the locale's appropriate time representation.

D_T_FMT

Always evaluates to %c, the locale's appropriate date and time representation.

ALT_DIGITS

Currently this gives the same results as Linux does. If you have examples of it needing to work differently, please file a report at https://github.com/Perl/perl5/issues.

ERA_D_FMT
ERA_T_FMT
ERA_D_T_FMT
T_FMT_AMPM

These are derived by using strftime(), and not all versions of that function know about them. "" is returned for these on such systems.

All _NL_foo items

These return the same values as they do on boxes that don't have the appropriate underlying locale categories.

See your nl_langinfo(3) for more information about the available constants. (Often this means having to look directly at the langinfo.h C header file.)

EXPORT

By default only the langinfo() function is exported.

BUGS

Before Perl 5.28, the returned values are unreliable for the RADIXCHAR and THOUSEP locale constants.

Starting in 5.28, changing locales on threaded builds is supported on systems that offer thread-safe locale functions. These include POSIX 2008 systems and Windows starting with Visual Studio 2005, and this module will work properly in such situations. However, on threaded builds on Windows prior to Visual Studio 2015, retrieving the items CRNCYSTR and THOUSEP can result in a race with a thread that has converted to use the global locale. It is quite uncommon for a thread to have done this. It would be possible to construct a workaround for this; patches welcome: see "switch_to_global_locale" in perlapi.

SEE ALSO

perllocale, "localeconv" in POSIX, "setlocale" in POSIX, nl_langinfo(3).

AUTHOR

Jarkko Hietaniemi, <jhi@hut.fi>. Now maintained by Perl 5 porters.

COPYRIGHT AND LICENSE

Copyright 2001 by Jarkko Hietaniemi

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.