преобразовать строку широких символов в многобайтовую строку (convert a wide-character string to a multibyte string)
Имя (Name)
wcsnrtombs - convert a wide-character string to a multibyte
string
Синопсис (Synopsis)
#include <wchar.h>
size_t wcsnrtombs(char *restrict dest, const wchar_t **restrict src,
size_t nwc, size_t len, mbstate_t *restrict ps);
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
wcsnrtombs():
Since glibc 2.10:
_POSIX_C_SOURCE >= 200809L
Before glibc 2.10:
_GNU_SOURCE
Описание (Description)
The wcsnrtombs() function is like the wcsrtombs(3) function,
except that the number of wide characters to be converted,
starting at *src, is limited to nwc.
If dest is not NULL, the wcsnrtombs() function converts at most
nwc wide characters from the wide-character string *src to a
multibyte string starting at dest. At most len bytes are written
to dest. The shift state *ps is updated. The conversion is
effectively performed by repeatedly calling wcrtomb(dest, *src,
ps), as long as this call succeeds, and then incrementing dest by
the number of bytes written and *src by one. The conversion can
stop for three reasons:
1. A wide character has been encountered that can not be
represented as a multibyte sequence (according to the current
locale). In this case, *src is left pointing to the invalid
wide character, (size_t) -1 is returned, and errno is set to
EILSEQ.
2. nwc wide characters have been converted without encountering a
null wide character (L'\0'), or the length limit forces a
stop. In this case, *src is left pointing to the next wide
character to be converted, and the number of bytes written to
dest is returned.
3. The wide-character string has been completely converted,
including the terminating null wide character (which has the
side effect of bringing back *ps to the initial state). In
this case, *src is set to NULL, and the number of bytes
written to dest, excluding the terminating null byte ('\0'),
is returned.
If dest is NULL, len is ignored, and the conversion proceeds as
above, except that the converted bytes are not written out to
memory, and that no destination length limit exists.
In both of the above cases, if ps is NULL, a static anonymous
state known only to the wcsnrtombs() function is used instead.
The programmer must ensure that there is room for at least len
bytes at dest.
Возвращаемое значение (Return value)
The wcsnrtombs() function returns the number of bytes that make
up the converted part of multibyte sequence, not including the
terminating null byte. If a wide character was encountered which
could not be converted, (size_t) -1 is returned, and errno set to
EILSEQ.
Атрибуты (Attributes)
For an explanation of the terms used in this section, see
attributes(7).
┌─────────────┬───────────────┬──────────────────────────────────┐
│Interface │ Attribute │ Value │
├─────────────┼───────────────┼──────────────────────────────────┤
│wcsnrtombs() │ Thread safety │ MT-Unsafe race:wcsnrtombs/!ps │
└─────────────┴───────────────┴──────────────────────────────────┘
Стандарты (Conforming to)
POSIX.1-2008.
Примечание (Note)
The behavior of wcsnrtombs() depends on the LC_CTYPE category of
the current locale.
Passing NULL as ps is not multithread safe.
Смотри также (See also)
iconv(3), mbsinit(3), wcsrtombs(3)
