'\" t

.\" Copyright (C) 2014 Michael Kerrisk <mtk.manpages@gmail.com>

.\"

.\" %%%LICENSE_START(VERBATIM)

.\" Permission is granted to make and distribute verbatim copies of this

.\" manual provided the copyright notice and this permission notice are

.\" preserved on all copies.

.\"

.\" Permission is granted to copy and distribute modified versions of this

.\" manual under the conditions for verbatim copying, provided that the

.\" entire resulting derived work is distributed under the terms of a

.\" permission notice identical to this one.

.\"

.\" Since the Linux kernel and libraries are constantly changing, this

.\" manual page may be incorrect or out-of-date.  The author(s) assume no

.\" responsibility for errors or omissions, or for damages resulting from

.\" the use of the information contained herein.  The author(s) may not

.\" have taken the same level of care in the production of this manual,

.\" which is licensed free of charge, as they might when working

.\" professionally.

.\"

.\" Formatted or processed versions of this manual, if unaccompanied by

.\" the source, must acknowledge the copyright and authors of this work.

.\" %%%LICENSE_END

.\"

.TH USELOCALE 3 2017-09-15 "Linux" "Linux Programmer's Manual"

.SH NAME

uselocale \- set/get the locale for the calling thread

.SH SYNOPSIS

.nf

.B #include <locale.h>

.PP

.BI "locale_t uselocale(locale_t " newloc );

.fi

.PP

.in -4n

Feature Test Macro Requirements for glibc (see

.BR feature_test_macros (7)):

.in

.PP

.BR uselocale ():

.PD 0

.RS 4

.TP

Since glibc 2.10:

_XOPEN_SOURCE\ >=\ 700

.TP

Before glibc 2.10:

_GNU_SOURCE

.RE

.PD

.SH DESCRIPTION

The

.BR uselocale ()

function sets the current locale for the calling thread,

and returns the thread's previously current locale.

After a successful call to

.BR uselocale (),

any calls by this thread to functions that depend on the locale

will operate as though the locale has been set to

.IR newloc .

.PP

The

.I newloc

argument can have one of the following values:

.TP

A handle returned by a call to \fBnewlocale\fP(3) or \fBduplocale\fP(3)

The calling thread's current locale is set to the specified locale.

.TP

The special locale object handle \fBLC_GLOBAL_LOCALE\fP

The calling thread's current locale is set to the global locale determined by

.BR setlocale (3).

.TP

.I "(locale_t) 0"

The calling thread's current locale is left unchanged

(and the current locale is returned as the function result).

.SH RETURN VALUE

On success,

.BR uselocale ()

returns the locale handle that was set by the previous call to

.BR uselocale ()

in this thread, or

.BR LC_GLOBAL_HANDLE

if there was no such previous call.

On error, it returns

.IR "(locale_t)\ 0",

and sets

.I errno

to indicate the cause of the error.

.SH ERRORS

.TP

.B EINVAL

.I newloc

does not refer to a valid locale object.

.SH VERSIONS

The

.BR uselocale ()

function first appeared in version 2.3 of the GNU C library.

.SH CONFORMING TO

POSIX.1-2008.

.SH NOTES

Unlike

.BR setlocale (3),

.BR uselocale ()

does not allow selective replacement of individual locale categories.

To employ a locale that differs in only a few categories from the current

locale, use calls to

.BR duplocale (3)

and

.BR newlocale (3)

to obtain a locale object equivalent to the current locale and

modify the desired categories in that object.

.SH EXAMPLE

See

.BR newlocale (3)

and

.BR duplocale (3).

.SH SEE ALSO

.BR locale (1),

.BR duplocale (3),

.BR freelocale (3),

.BR newlocale (3),

.BR setlocale (3),

.BR locale (5),

.BR locale (7)

.SH COLOPHON

This page is part of release 4.15 of the Linux

.I man-pages

project.

A description of the project,

information about reporting bugs,

and the latest version of this page,

can be found at

\%https://www.kernel.org/doc/man\-pages/.