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 lo-
       cale information in a more flexible way than  localeconv(3).   nl_lang-
       info() 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.  setlocale(3) needs to be executed with proper  arguments  be-
       fore.

       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 char-
              acter 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  strf-
              time(3) to represent time and date in a locale-specific way.

       D_FMT (LC_TIME)
              Return  a  string  that can be used as a format string for strf-
              time(3) to represent a date in a locale-specific way.

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

       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  conven-
              tion (ISO 8601) that Monday is the first day of the week.]

       ABDAY_{1-7} (LC_TIME)
              Return abbreviated name of the n-th day of the week.

       MON_{1-12} (LC_TIME)
              Return name of the n-th month.

       ABMON_{1-12} (LC_TIME)
              Return abbreviated name of the n-th month.

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

       THOUSEP (LC_NUMERIC)
              Return  separator  character for thousands (groups of three dig-
              its).

       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 charac-
              ter.

       The  above  list  covers  just  some  examples of items that can be re-
       quested.  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 cat-
       egory,  nl_langinfo()  return  a pointer to the corresponding string in
       the "C" locale.  The same is true of nl_langinfo_l() if  locale  speci-
       fies 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 sub-
       sequent  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  at-
       tributes(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.

EXAMPLE
       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
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       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                               2019-03-06                    NL_LANGINFO(3)