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

       uselocale — use locale in current thread

SYNOPSIS

       #include <locale.h>

       locale_t uselocale(locale_t newloc);

DESCRIPTION

       The uselocale() function shall set the current locale for the current thread to the locale
       represented by newloc.

       The value for the newloc argument shall be one of the following:

        1. A value returned by the newlocale() or duplocale() functions

        2. The special locale object descriptor LC_GLOBAL_LOCALE

        3. (locale_t)0

       Once the uselocale() function has been  called  to  install  a  thread-local  locale,  the
       behavior  of  every interface using data from the current locale shall be affected for the
       calling thread. The current locale for other threads shall remain unchanged.

       If the newloc argument is (locale_t)0, the  object  returned  is  the  current  locale  or
       LC_GLOBAL_LOCALE if there has been no previous call to uselocale() for the current thread.

       If  the  newloc  argument  is  LC_GLOBAL_LOCALE,  the  thread  shall use the global locale
       determined by the setlocale() function.

RETURN VALUE

       Upon successful completion, the uselocale() function shall return the locale  handle  from
       the  previous  call  for  the  current  thread,  or  LC_GLOBAL_LOCALE if there was no such
       previous call.  Otherwise, uselocale() shall return (locale_t)0 and set errno to  indicate
       the error.

ERRORS

       The uselocale() function may fail if:

       EINVAL locale is not a valid locale object.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       Unlike  the  setlocale()  function, the uselocale() function does not allow replacing some
       locale categories only. Applications that need to install a locale which differs only in a
       few  categories must use newlocale() to change a locale object equivalent to the currently
       used locale and install it.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       duplocale(), freelocale(), newlocale(), setlocale()

       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  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 .