I18N::Langinfo - query locale information
use I18N::Langinfo;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_12For the date-time, date, and time formats used by the strftime() function (see POSIX):
D_T_FMT D_FMT T_FMTFor the locales for which it makes sense to have ante meridiem and post meridiem time formats:
AM_STR PM_STR T_FMT_AMPMFor the character code set being used (such as "ISO8859-1", "cp850", "koi8-r", "sjis", "utf8", etc.):
CODESETFor the symbol or string of characters that indicates a number is a monetary value:
CRNCYSTRAn 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:
For the radix character used between the integer and the fractional part of decimal numbers, and the group separator string for large-ish floating point numbers (yes, these are redundant with POSIX::localeconv()):
RADIXCHAR THOUSEPFor any alternate digits used in this locale besides the standard 0..9:
ALT_DIGITSThis returns a sequence of alternate numeric reprsesentations for the numbers 0 ... up to 99. The representations are returned in a single string, with a semi-colon ; used to separated the individual ones.
Most locales don't have alternate digits, so the string will be empty.
To access this data conveniently, you could do something like
use I18N::Langinfo qw(langinfo ALT_DIGITS);
my @alt_digits = split ';', langinfo(ALT_DIGITS);The array @alt_digits will contain 0 elements if the current locale doesn't have alternate digits specified for it. Otherwise, it will have as many elements as the locale defines, with [0] containing the alternate digit for zero; [1] for one; and so forth, up to potentially [99] for the alternate representation of ninety-nine.
Be aware that the alternate representation in some locales for the numbers 0..9 will have a leading alternate-zero, so would look like the equivalent of 00..09.
Running this program
use I18N::Langinfo qw(langinfo ALT_DIGITS);
my @alt_digits = split ';', langinfo(ALT_DIGITS);
splice @alt_digits, 15;
print join " ", @alt_digits, "\n";on a Japanese locale yields
〇 一 二 三 四 五 六 七 八 九 十 十一 十二 十三 十四
on some platforms.
For the affirmative and negative responses and expressions:
YESSTR YESEXPR NOSTR NOEXPRFor 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_FMTIn 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_LIBOn 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_CATEGORYOn 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_MEASUREMENTOn 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_MSOn 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_WIDTHOn 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_PREFIXOn 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
nl_langinfoThis 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:
ERAUnimplemented, so returns "".
CODESETThis 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 "".
YESEXPRYESSTRNOEXPRNOSTROnly 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.
ALT_DIGITSOn systems with a strftime(3) that recognizes the POSIX-defined %O format modifier (not Windows), perl tries hard to return these. The result likely will go as high as what nl_langinfo() would return, but not necessarily; and the numbers from 0..9 will always be stripped of leading zeros.
Without %O, an empty string is always returned.
D_FMTAlways evaluates to %x, the locale's appropriate date representation.
T_FMTAlways evaluates to %X, the locale's appropriate time representation.
D_T_FMTAlways evaluates to %c, the locale's appropriate date and time representation.
CRNCYSTRThe return may be incorrect for those rare locales where the currency symbol replaces the radix character. If you have examples of it needing to work differently, please file a report at https://github.com/Perl/perl5/issues.
ERA_D_FMTERA_T_FMTERA_D_T_FMTT_FMT_AMPMThese are derived by using strftime(), and not all versions of that function know about them. "" is returned for these on such systems.
_NL_foo itemsThese 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.)
By default only the langinfo() function is exported.
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.
perllocale, "localeconv" in POSIX, "setlocale" in POSIX, nl_langinfo(3).
Jarkko Hietaniemi, <jhi@hut.fi>. Now maintained by Perl 5 porters.
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.