создать или изменить объект локали (create or modify a locale object)
Пролог (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.
Имя (Name)
newlocale — create or modify a locale object
Синопсис (Synopsis)
#include <locale.h>
locale_t newlocale(int category_mask, const char *locale,
locale_t base);
Описание (Description)
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 object created.
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
implementation-defined 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 default locale.
The following preset values of locale are defined for all
settings of category_mask:
"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.1‐2017, 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 and unchanged.
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.
Возвращаемое значение (Return value)
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.
Ошибки (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 valid category.
ENOENT For any of the categories in category_mask, the locale
data is not available.
The newlocale() function may fail if:
EINVAL The locale argument is not a valid string pointer.
The following sections are informative.
Примеры (Examples)
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 loc2:
#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)
abort ();
/* 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():
#include <locale.h>
...
/* Every locale object allocated with newlocale() should be
* freed using freelocale():
*/
locale_t loc;
/* Get the locale. */
loc = newlocale (LC_CTYPE_MASK | LC_TIME_MASK, "locname", (locale_t)0);
/* ... Use the locale object ... */
...
/* Free the locale object resources. */
freelocale (loc);
Использование в приложениях (Application usage)
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.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
None.
Смотри также (See also)
duplocale(3p), freelocale(3p), uselocale(3p)
The Base Definitions volume of POSIX.1‐2017, Chapter 7, Locale,
Chapter 8, Environment Variables, locale.h(0p)
