nl_langinfo

NL_LANGINFO(3)              Linux Programmer's Manual             NL_LANGINFO(3)



NAME
       nl_langinfo, nl_langinfo_l - query language and locale information

SYNOPSIS
       #include <langinfo.h>

       char *nl_langinfo(nl_item item);

       char *nl_langinfo_l(nl_item item, locale_t locale);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       nl_langinfo_l():
           Since glibc 2.24:
               _POSIX_C_SOURCE >= 200809L
           Glibc 2.23 and earlier:
               _POSIX_C_SOURCE >= 200112L

DESCRIPTION
       The nl_langinfo() and nl_langinfo_l() functions provide access to locale
       information in a more flexible way than localeconv(3).  nl_langinfo()
       returns a string which is the value corresponding to item in the
       program's current global locale.  nl_langinfo_l() returns a string which
       is the value corresponding to item for the locale identified by the
       locale object locale, which was previously created by newlocale(1).
       Individual and additional elements of the locale categories can be
       queried.

       Examples for the locale elements that can be specified in item using the
       constants defined in <langinfo.h> are:

       CODESET (LC_CTYPE)
              Return a string with the name of the character encoding used in
              the selected locale, such as "UTF-8", "ISO-8859-1", or
              "ANSI_X3.4-1968" (better known as US-ASCII).  This is the same
              string that you get with "locale charmap".  For a list of
              character encoding names, try "locale -m" (see locale(1)).

       D_T_FMT (LC_TIME)
              Return a string that can be used as a format string for
              strftime(3) to represent time and date in a locale-specific way
              (%c conversion specification).

       D_FMT (LC_TIME)
              Return a string that can be used as a format string for
              strftime(3) to represent a date in a locale-specific way (%x
              conversion specification).

       T_FMT (LC_TIME)
              Return a string that can be used as a format string for
              strftime(3) to represent a time in a locale-specific way (%X
              conversion specification).

       AM_STR (LC_TIME)
              Return a string that represents affix for ante meridiem (before
              noon, "AM") time.  (Used in %p strftime(3) conversion
              specification.)

       PM_STR (LC_TIME)
              Return a string that represents affix for post meridiem (before
              midnight, "PM") time.  (Used in %p strftime(3) conversion
              specification.)

       T_FMT_AMPM (LC_TIME)
              Return a string that can be used as a format string for
              strftime(3) to represent a time in a.m. or p.m. notation a locale-
              specific way (%r conversion specification).

       ERA (LC_TIME)
              Return era description, which contains information about how years
              are counted and displayed for each era in a locale.  Each era
              description segment shall have the format:

                     direction:offset:start_date:end_date:era_name:era_format

              according to the definitions below:

              direction   Either a "+" or a "-" character.  The "+" means that
                          years increase from the start_date towards the
                          end_date, "-" means the opposite.

              offset      The epoch year of the start_date.

              start_date  A date in the form yyyy/mm/dd, where yyyy, mm, and dd
                          are the year, month, and day numbers respectively of
                          the start of the era.

              end_date    The ending date of the era, in the same format as the
                          start_date, or one of the two special values "-*"
                          (minus infinity) or "+*" (plus infinity).

              era_name    The name of the era, corresponding to the %EC
                          strftime(3) conversion specification.

              era_format  The format of the year in the era, corresponding to
                          the %EY strftime(3) conversion specification.

              Era description segments are separated by semicolons.  Most
              locales do not define this value.  Examples of locales that do
              define this value are the Japanese and Thai locales.

       ERA_D_T_FMT (LC_TIME)
              Return a string that can be used as a format string for
              strftime(3) for alternative representation of time and date in a
              locale-specific way (%Ec conversion specification).

       ERA_D_FMT (LC_TIME)
              Return a string that can be used as a format string for
              strftime(3) for alternative representation of a date in a locale-
              specific way (%Ex conversion specification).

       ERA_T_FMT (LC_TIME)
              Return a string that can be used as a format string for
              strftime(3) for alternative representation of a time in a locale-
              specific way (%EX conversion specification).

       DAY_{1–7} (LC_TIME)
              Return name of the n-th day of the week. [Warning: this follows
              the US convention DAY_1 = Sunday, not the international convention
              (ISO 8601) that Monday is the first day of the week.]  (Used in %A
              strftime(3) conversion specification.)

       ABDAY_{1–7} (LC_TIME)
              Return abbreviated name of the n-th day of the week.  (Used in %a
              strftime(3) conversion specification.)

       MON_{1–12} (LC_TIME)
              Return name of the n-th month.  (Used in %B strftime(3) conversion
              specification.)

       ABMON_{1–12} (LC_TIME)
              Return abbreviated name of the n-th month.  (Used in %b
              strftime(3) conversion specification.)

       RADIXCHAR (LC_NUMERIC)
              Return radix character (decimal dot, decimal comma, etc.).

       THOUSEP (LC_NUMERIC)
              Return separator character for thousands (groups of three digits).

       YESEXPR (LC_MESSAGES)
              Return a regular expression that can be used with the regex(3)
              function to recognize a positive response to a yes/no question.

       NOEXPR (LC_MESSAGES)
              Return a regular expression that can be used with the regex(3)
              function to recognize a negative response to a yes/no question.

       CRNCYSTR (LC_MONETARY)
              Return the currency symbol, preceded by "-" if the symbol should
              appear before the value, "+" if the symbol should appear after the
              value, or "." if the symbol should replace the radix character.

       The above list covers just some examples of items that can be requested.
       For a more detailed list, consult The GNU C Library Reference Manual.

RETURN VALUE
       On success, these functions return a pointer to a string which is the
       value corresponding to item in the specified locale.

       If no locale has been selected by setlocale(3) for the appropriate
       category, nl_langinfo() return a pointer to the corresponding string in
       the "C" locale.  The same is true of nl_langinfo_l() if locale specifies
       a locale where langinfo data is not defined.

       If item is not valid, a pointer to an empty string is returned.

       The pointer returned by these functions may point to static data that may
       be overwritten, or the pointer itself may be invalidated, by a subsequent
       call to nl_langinfo(), nl_langinfo_l(), or setlocale(3).  The same
       statements apply to nl_langinfo_l() if the locale object referred to by
       locale is freed or modified by freelocale(3) or newlocale(3).

       POSIX specifies that the application may not modify the string returned
       by these functions.

ATTRIBUTES
       For an explanation of the terms used in this section, see attributes(7).

       ┌──────────────┬───────────────┬────────────────┐
       │Interface     Attribute     Value          │
       ├──────────────┼───────────────┼────────────────┤
       │nl_langinfo() │ Thread safety │ MT-Safe locale │
       └──────────────┴───────────────┴────────────────┘
CONFORMING TO
       POSIX.1-2001, POSIX.1-2008, SUSv2.

NOTES
       The behavior of nl_langinfo_l() is undefined if locale is the special
       locale object LC_GLOBAL_LOCALE or is not a valid locale object handle.

EXAMPLES
       The following program sets the character type and the numeric locale
       according to the environment and queries the terminal character set and
       the radix character.

       #include <langinfo.h>
       #include <locale.h>
       #include <stdio.h>
       #include <stdlib.h>

       int
       main(int argc, char *argv[])
       {
           setlocale(LC_CTYPE, "");
           setlocale(LC_NUMERIC, "");

           printf("%s\n", nl_langinfo(CODESET));
           printf("%s\n", nl_langinfo(RADIXCHAR));

           exit(EXIT_SUCCESS);
       }

SEE ALSO
       locale(1), localeconv(3), setlocale(3), charsets(7), locale(7)

       The GNU C Library Reference Manual

COLOPHON
       This page is part of release 5.09 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.



GNU                                2020-04-11                     NL_LANGINFO(3)