PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

NL_LANGINFO(3P)           POSIX Programmer's Manual          NL_LANGINFO(3P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior), or
       the interface may not be implemented on Linux.

NAME         top

       nl_langinfo, nl_langinfo_l — language information

SYNOPSIS         top

       #include <langinfo.h>

       char *nl_langinfo(nl_item item);
       char *nl_langinfo_l(nl_item item, locale_t locale);

DESCRIPTION         top

       The nl_langinfo() and nl_langinfo_l() functions shall return a
       pointer to a string containing information relevant to the particular
       language or cultural area defined in the current locale, or in the
       locale represented by locale, respectively (see <langinfo.h>).  The
       manifest constant names and values of item are defined in
       <langinfo.h>.  For example:

           nl_langinfo(ABDAY_1)

       would return a pointer to the string "Dom" if the identified language
       was Portuguese, and "Sun" if the identified language was English.

           nl_langinfo_l(ABDAY_1, loc)

       would return a pointer to the string "Dom" if the identified language
       of the locale represented by loc was Portuguese, and "Sun" if the
       identified language of the locale represented by loc was English.

       The nl_langinfo() function need not be thread-safe.

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

RETURN VALUE         top

       In a locale where langinfo data is not defined, these functions shall
       return a pointer to the corresponding string in the POSIX locale. In
       all locales, these functions shall return a pointer to an empty
       string if item contains an invalid setting.

       The application shall not modify the string returned. The pointer
       returned by nl_langinfo() might be invalidated or the string content
       might be overwritten by a subsequent call to nl_langinfo() in any
       thread or to nl_langinfo_l() in the same thread or the initial
       thread, by subsequent calls to setlocale() with a category
       corresponding to the category of item (see <langinfo.h>) or the
       category LC_ALL, or by subsequent calls to uselocale() which change
       the category corresponding to the category of item.  The pointer
       returned by nl_langinfo_l() might be invalidated or the string
       content might be overwritten by a subsequent call to nl_langinfo_l()
       in the same thread or to nl_langinfo() in any thread, or by
       subsequent calls to freelocale() or newlocale() which free or modify
       the locale object that was passed to nl_langinfo_l().

ERRORS         top

       No errors are defined.

       The following sections are informative.

EXAMPLES         top

   Getting Date and Time Formatting Information
       The following example returns a pointer to a string containing date
       and time formatting information, as defined in the LC_TIME category
       of the current locale.

           #include <time.h>
           #include <langinfo.h>
           ...
           strftime(datestring, sizeof(datestring), nl_langinfo(D_T_FMT), tm);
           ...

APPLICATION USAGE         top

       The array pointed to by the return value should not be modified by
       the program, but may be modified by further calls to these functions.

RATIONALE         top

       The possible interactions between internal data used by nl_langinfo()
       and nl_langinfo_l() are complicated by the fact that nl_langinfo_l()
       must be thread-safe but nl_langinfo() need not be. The various
       implementation choices are:

        1. nl_langinfo_l() and nl_langinfo() use separate buffers, or at
           least one of them does not use an internal string buffer. In this
           case there are no interactions.

        2. nl_langinfo_l() and nl_langinfo() share an internal per-thread
           buffer. There can be interactions, but only in the same thread.

        3. nl_langinfo_l() uses an internal per-thread buffer, and
           nl_langinfo() uses (in all threads) the same buffer that
           nl_langinfo_l() uses in the initial thread. There can be
           interactions, but only when nl_langinfo_l() is called in the
           initial thread.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       setlocale(3p), uselocale(3p)

       The Base Definitions volume of POSIX.1‐2008, Chapter 7, Locale,
       langinfo.h(0p), locale.h(0p), nl_types.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) In the event of any discrepancy between this version and
       the original IEEE and The Open Group Standard, the original IEEE and
       The Open Group Standard is the referee document. The original
       Standard can be obtained online at http://www.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                     NL_LANGINFO(3P)

Pages that refer to this page: langinfo.h(0p)nl_types.h(0p)localeconv(3p)setlocale(3p)