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DUPLOCALE(3P)              POSIX Programmer's Manual             DUPLOCALE(3P)
PROLOG
       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
       duplocale -- duplicate a locale object
SYNOPSIS
       #include <locale.h>
       locale_t duplocale(locale_t locobj);
DESCRIPTION
       The duplocale() function shall create a duplicate copy  of  the  locale
       object referenced by the locobj argument.
       If  the locobj argument is LC_GLOBAL_LOCALE, duplocale() shall create a
       new locale object containing a copy of the global locale determined  by
       the setlocale() function.
       The  behavior is undefined if the locobj argument is not a valid locale
       object handle.
RETURN VALUE
       Upon successful completion, the duplocale()  function  shall  return  a
       handle  for  a  new  locale object. Otherwise, duplocale() shall return
       (locale_t)0 and set errno to indicate the error.
ERRORS
       The duplocale() function shall fail if:
       ENOMEM There is not enough memory available to create the locale object
              or load the locale data.
       The following sections are informative.
EXAMPLES
   Constructing an Altered Version of an Existing Locale Object
       The  following  example  shows  a  code  fragment  to create a slightly
       altered version of an existing locale  object.  The  function  takes  a
       locale  object  and  a locale name and it replaces the LC_TIME category
       data in the locale object with that from the named locale.
           #include <locale.h>
           ...
           locale_t
           with_changed_lc_time (locale_t obj, const char *name)
           {
               locale_t retval = duplocale (obj);
               if (retval != (locale_t) 0)
               {
                   locale_t changed = newlocale (LC_TIME_MASK, name, retval);
                   if (changed == (locale_t) 0)
                       /* An error occurred. Free all allocated resources. */
                       freelocale (retval);
                   retval = changed;
               }
               return retval; }
           }
APPLICATION USAGE
       The use of the duplocale() function is recommended for situations where
       a  locale  object  is being used in multiple places, and it is possible
       that the lifetime of the locale object might end before  all  uses  are
       finished.  Another reason to duplicate a locale object is if a slightly
       modified form is needed.  This can be achieved by a call to newlocale()
       following the duplocale() call.
       As with the newlocale() function, handles for locale objects created by
       the duplocale() function should be released by a corresponding call  to
       freelocale().
       The  duplocale()  function  can also be used in conjunction with uselo-
       cale((locale_t)0).  This returns the locale in effect for  the  calling
       thread,    but   can   have   the   value   LC_GLOBAL_LOCALE.   Passing
       LC_GLOBAL_LOCALE to functions such as isalnum_l() results in  undefined
       behavior,  but  applications can convert it into a usable locale object
       by using duplocale().
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       freelocale(), newlocale(), uselocale()
       The Base Definitions volume of POSIX.1-2008, <locale.h>
COPYRIGHT
       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 Electri-
       cal 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.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013                        DUPLOCALE(3P)