USELOCALE(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
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 .