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.
The newlocale() function shall create a new locale object or modify
an existing one. If the base argument is (locale_t)0, a new locale
object shall be created. It is unspecified whether the locale object
pointed to by base shall be modified, or freed and a new locale
The category_mask argument specifies the locale categories to be set
or modified. Values for category_mask shall be constructed by a
bitwise-inclusive OR of the symbolic constants LC_CTYPE_MASK,
LC_NUMERIC_MASK, LC_TIME_MASK, LC_COLLATE_MASK, LC_MONETARY_MASK, and
LC_MESSAGES_MASK, or any of the other implementation-defined
LC_*_MASK values defined in <locale.h>.
For each category with the corresponding bit set in category_mask the
data from the locale named by locale shall be used. In the case of
modifying an existing locale object, the data from the locale named
by locale shall replace the existing data within the locale object.
If a completely new locale object is created, the data for all
sections not requested by category_mask shall be taken from the
The following preset values of locale are defined for all settings of
"POSIX" Specifies the minimal environment for C-language
translation called the POSIX locale.
"C" Equivalent to "POSIX".
"" Specifies an implementation-defined native environment.
This corresponds to the value of the associated
environment variables, LC_* and LANG; see the Base
Definitions volume of POSIX.1‐2008, Chapter 7, Locale and
Chapter 8, Environment Variables.
If the base argument is not (locale_t)0 and the newlocale() function
call succeeds, the contents of base are unspecified. Applications
shall ensure that they stop using base as a locale object before
calling newlocale(). If the function call fails and the base
argument is not (locale_t)0, the contents of base shall remain valid
The behavior is undefined if the base argument is the special locale
object LC_GLOBAL_LOCALE, or is not a valid locale object handle and
is not (locale_t)0.
Upon successful completion, the newlocale() function shall return a
handle which the caller may use on subsequent calls to duplocale(),
freelocale(), and other functions taking a locale_t argument.
Upon failure, the newlocale() function shall return (locale_t)0 and
set errno to indicate the error.
The newlocale() function shall fail if:
ENOMEM There is not enough memory available to create the locale
object or load the locale data.
EINVAL The category_mask contains a bit that does not correspond to a
ENOENT For any of the categories in category_mask, the locale data is
The newlocale() function may fail if:
EINVAL The locale argument is not a valid string pointer.
The following sections are informative.
Constructing a Locale Object from Different Locales
The following example shows the construction of a locale where the
LC_CTYPE category data comes from a locale loc1 and the LC_TIME
category data from a locale tok2:
#include <locale.h>...locale_t loc, new_loc;
/* Get the "loc1" data. */
loc = newlocale (LC_CTYPE_MASK, "loc1", (locale_t)0);
if (loc == (locale_t) 0)
/* Get the "loc2" data. */
new_loc = newlocale (LC_TIME_MASK, "loc2", loc);
if (new_loc != (locale_t) 0)
/* We don t abort if this fails. In this case this
simply used to unchanged locale object. */
loc = new_loc;
Freeing up a Locale Object
The following example shows a code fragment to free a locale object
created by newlocale():
/* Every locale object allocated with newlocale() should be
* freed using freelocale():
/* Get the locale. */
loc = newlocale (LC_CTYPE_MASK | LC_TIME_MASK, "locname", (locale_t)0);
/* ... Use the locale object ... */
/* Free the locale object resources. */
Handles for locale objects created by the newlocale() function should
either be released by a corresponding call to freelocale(), or be
used as a base locale to another newlocale() call.
The special locale object LC_GLOBAL_LOCALE must not be passed for the
base argument, even when returned by the uselocale() function.
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
IEEE/The Open Group 2013 NEWLOCALE(3P)