This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       None.

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for  Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical  and  Electronics
       Engineers, Inc and The Open Group.  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.opengroup.org/unix/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                                   2017                                      locale.h(7POSIX)

       Some of the functionality described on this reference page extends the ISO C standard. Applications shall
       define the appropriate feature test macro (see the System Interfaces volume of POSIX.1‐2017, Section2.2,
       TheCompilationEnvironment) to enable the visibility of these symbols in this header.

       The  <locale.h>  header  shall  define  the  lconv  structure, which shall include at least the following
       members.  (See  the  definitions  of  LC_MONETARY  in  Section7.3.3,  LC_MONETARY  and  Section7.3.4,
       LC_NUMERIC.)

           char    *currency_symbol
           char    *decimal_point
           char     frac_digits
           char    *grouping
           char    *int_curr_symbol
           char     int_frac_digits
           char     int_n_cs_precedes
           char     int_n_sep_by_space
           char     int_n_sign_posn
           char     int_p_cs_precedes
           char     int_p_sep_by_space
           char     int_p_sign_posn
           char    *mon_decimal_point
           char    *mon_grouping
           char    *mon_thousands_sep
           char    *negative_sign
           char     n_cs_precedes
           char     n_sep_by_space
           char     n_sign_posn
           char    *positive_sign
           char     p_cs_precedes
           char     p_sep_by_space
           char     p_sign_posn
           char    *thousands_sep

       The  <locale.h>  header  shall  define  NULL  (as  described in <stddef.h>) and at least the following as
       macros:

       LC_ALL
       LC_COLLATE
       LC_CTYPE
       LC_MESSAGES
       LC_MONETARY
       LC_NUMERIC
       LC_TIME

       which shall expand to integer constant expressions with distinct values for use as the first argument  to
       the setlocale() function.

       Additional  macro  definitions,  beginning  with  the characters LC_ and an uppercase letter, may also be
       specified by the implementation.

       The <locale.h> header shall contain at least the following macros representing bitmasks for use with  the
       newlocale()  function  for each supported locale category: LC_COLLATE_MASK LC_CTYPE_MASK LC_MESSAGES_MASK
       LC_MONETARY_MASK LC_NUMERIC_MASK LC_TIME_MASK

       In addition, a macro to set the bits for all categories set shall be defined: LC_ALL_MASK

       The <locale.h> header shall define LC_GLOBAL_LOCALE, a special  locale  object  descriptor  used  by  the
       duplocale() and uselocale() functions.

       The <locale.h> header shall define the locale_t type, representing a locale object.

       The following shall be declared as functions and may also be defined as macros. Function prototypes shall
       be provided for use with ISO C standard compilers.

           locale_t      duplocale(locale_t);
           void          freelocale(locale_t);
           struct lconv *localeconv(void);
           locale_t      newlocale(int, const char *, locale_t);
           char         *setlocale(int, const char *);
           locale_t      uselocale (locale_t);

       Thefollowingsectionsareinformative.

       None.

       locale.h — category macros

       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.

       It  is  suggested  that  each  category macro name for use in setlocale() have a corresponding macro name
       ending in _MASK for use in newlocale().

Chapter8, EnvironmentVariables, <stddef.h>

       The System Interfaces volume  of  POSIX.1‐2017,  duplocale(),  freelocale(),  localeconv(),  newlocale(),
       setlocale(), uselocale()

       #include <locale.h>