преобразовать многобайтовую строку в строку расширенных символов (convert a multibyte string to a wide-character string)
Имя (Name)
mbsrtowcs - convert a multibyte string to a wide-character string
Синопсис (Synopsis)
#include <wchar.h>
size_t mbsrtowcs(wchar_t *restrict dest, const char **restrict src,
size_t len, mbstate_t *restrict ps);
Описание (Description)
If dest is not NULL, the mbsrtowcs() function converts the
multibyte string *src to a wide-character string starting at
dest. At most len wide characters are written to dest. The
shift state *ps is updated. The conversion is effectively
performed by repeatedly calling mbrtowc(dest, *src, n, ps) where
n is some positive number, as long as this call succeeds, and
then incrementing dest by one and *src by the number of bytes
consumed. The conversion can stop for three reasons:
1. An invalid multibyte sequence has been encountered. In this
case, *src is left pointing to the invalid multibyte sequence,
(size_t) -1 is returned, and errno is set to EILSEQ.
2. len non-L'\0' wide characters have been stored at dest. In
this case, *src is left pointing to the next multibyte
sequence to be converted, and the number of wide characters
written to dest is returned.
3. The multibyte string has been completely converted, including
the terminating null wide character ('\0'), 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 wide characters
written to dest, excluding the terminating null wide
character, is returned.
If dest is NULL, len is ignored, and the conversion proceeds as
above, except that the converted wide characters are not written
out to memory, and that no length limit exists.
In both of the above cases, if ps is NULL, a static anonymous
state known only to the mbsrtowcs() function is used instead.
The programmer must ensure that there is room for at least len
wide characters at dest.
Возвращаемое значение (Return value)
The mbsrtowcs() function returns the number of wide characters
that make up the converted part of the wide-character string, not
including the terminating null wide character. If an invalid
multibyte sequence was encountered, (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 │
├────────────┼───────────────┼───────────────────────────────────┤
│mbsrtowcs() │ Thread safety │ MT-Unsafe race:mbsrtowcs/!ps │
└────────────┴───────────────┴───────────────────────────────────┘
Стандарты (Conforming to)
POSIX.1-2001, POSIX.1-2008, C99.
Примечание (Note)
The behavior of mbsrtowcs() depends on the LC_CTYPE category of
the current locale.
Passing NULL as ps is not multithread safe.
Смотри также (See also)
iconv(3), mbrtowc(3), mbsinit(3), mbsnrtowcs(3), mbstowcs(3)
