USELOCALE(3)               POSIX Programmer's Manual              USELOCALE(3)



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


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 .



IEEE/The Open Group                  2013                         USELOCALE(3)
