.\"	$OpenBSD: newlocale.3,v 1.3 2019/06/25 17:40:24 schwarze Exp $
.\"
.\" Copyright (c) 2017 Ingo Schwarze <schwarze@openbsd.org>
.\"
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.Dd $Mdocdate: June 25 2019 $
.Dt NEWLOCALE 3
.Os
.Sh NAME
.Nm newlocale ,
.Nm duplocale ,
.Nm freelocale
.Nd create and destroy locale objects
.Sh SYNOPSIS
.In locale.h
.Ft locale_t
.Fo newlocale
.Fa "int mask"
.Fa "const char *locname"
.Fa "locale_t oldloc"
.Fc
.Ft locale_t
.Fo duplocale
.Fa "locale_t oldloc"
.Fc
.Ft void
.Fo freelocale
.Fa "locale_t oldloc"
.Fc
.Sh DESCRIPTION
The function
.Fn newlocale
creates a new locale object for use with
.Xr uselocale 3
and with many functions that accept
.Vt locale_t
arguments.
Locale categories not contained in the
.Fa mask
are copied from
.Fa oldloc
to the new locale object, or from the
.Qq C
locale if
.Fa oldloc
is
.Po Vt locale_t Pc Ns 0 .
.Pp
On
.Ox ,
.Fa locname
only affects the return value if
.Fa mask
includes
.Dv LC_CTYPE_MASK ,
and
.Fa locname
is only meaningful if it is
.Qq C
or
.Qq POSIX ,
if it ends with
.Qq .UTF-8 ,
or if it is an empty string.
Other
.Fa locname
arguments have the same effect as
.Qq C .
.Pp
The function
.Fn duplocale
copies
.Fa oldloc ,
or the global locale if given the special argument
.Dv LC_GLOBAL_LOCALE .
.Pp
For portability, when an object returned from
.Fn newlocale
or
.Fn duplocale
is no longer needed, pass it to
.Fn freelocale ,
even though the latter has no effect on
.Ox .
The
.Fa oldloc
objects passed to
.Fn newlocale
or
.Fn freelocale
become invalid, and using them or passing them once again to
.Fn freelocale
results in undefined behaviour, whereas objects passed to
.Fn duplocale
remain valid and can be passed to
.Fn freelocale
later on.
.Sh RETURN VALUES
The functions
.Fn newlocale
and
.Fn duplocale
return the new locale object on success or
.Po Vt locale_t Pc Ns 0
on failure.
.Sh ENVIRONMENT
If
.Fa locname
is an empty string,
.Fa newlocale
inspects
.Ev LC_ALL ,
.Ev LC_CTYPE ,
and
.Ev LANG
as described in
.Xr locale 1 .
.Sh ERRORS
The function
.Fn newlocale
fails if:
.Bl -tag -width Er
.It Bq Er EINVAL
An invalid bit is set in
.Fa mask ,
or
.Fa locname
is
.Dv NULL .
.It Bq Er ENOENT
Locale data is not available for
.Fa locname .
.El
.Pp
On other operating systems,
.Fn newlocale
and
.Fn duplocale
may also fail with
.Er ENOMEM .
.Sh SEE ALSO
.Xr iswalnum 3 ,
.Xr iswctype 3 ,
.Xr towctrans 3 ,
.Xr towlower 3 ,
.Xr uselocale 3 ,
.Xr wcscasecmp 3 ,
.Xr wctrans 3 ,
.Xr wctype 3
.Sh STANDARDS
These functions conform to
.St -p1003.1-2008
including Technical Corrigendum 3.
.Sh HISTORY
These functions have been available since
.Ox 6.2 .
.Sh CAVEATS
Calling
.Fn newlocale
with an
.Fa oldloc
argument of
.Dv LC_GLOBAL_LOCALE
results in undefined behaviour.