uselocale(3p) — Linux manual page

USELOCALE(3P)           POSIX Programmer's Manual          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 or query the current locale
       for the calling thread.

       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

       If the newloc argument is (locale_t)0, the current locale shall
       not be changed; this value can be used to query the current
       locale setting. If the newloc argument is LC_GLOBAL_LOCALE, any
       thread-local locale for the calling thread shall be uninstalled;
       the thread shall again use the global locale as the current
       locale, and changes to the global locale shall affect the thread.
       Otherwise, the locale represented by newloc shall be installed as
       a thread-local locale to be used as the current locale for the
       calling thread.

       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.

RETURN VALUE

       Upon successful completion, the uselocale() function shall return
       a handle for the thread-local locale that was in use as the
       current locale for the calling thread on entry to the function,
       or LC_GLOBAL_LOCALE if no thread-local locale was in use.
       Otherwise, uselocale() shall return (locale_t)0 and set errno to
       indicate the error.

ERRORS

       The uselocale() function may fail if:

       EINVAL newloc is not a valid locale object and is not
              (locale_t)0.

       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(3p), freelocale(3p), newlocale(3p), setlocale(3p)

       The Base Definitions volume of POSIX.1‐2017, locale.h(0p)

COPYRIGHT

       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                     USELOCALE(3P)

Pages that refer to this page: locale.h(0p), duplocale(3p), freelocale(3p), isalnum(3p), isalpha(3p), isblank(3p), iscntrl(3p), isgraph(3p), islower(3p), isprint(3p), ispunct(3p), isspace(3p), isupper(3p), iswalnum(3p), iswalpha(3p), iswblank(3p), iswcntrl(3p), iswctype(3p), iswdigit(3p), iswgraph(3p), iswlower(3p), iswprint(3p), iswpunct(3p), iswspace(3p), iswupper(3p), iswxdigit(3p), localeconv(3p), newlocale(3p), nl_langinfo(3p), setlocale(3p), strftime(3p), tolower(3p), toupper(3p), towlower(3p), towupper(3p)

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