преобразовать многобайтовую последовательность в широкий символ (convert a multibyte sequence to a wide character)
Имя (Name)
mbtowc - convert a multibyte sequence to a wide character
Синопсис (Synopsis)
#include <stdlib.h>
int mbtowc(wchar_t *restrict
pwc, const char *restrict
s, size_t
n);
Описание (Description)
The main case for this function is when s is not NULL and pwc is
not NULL. In this case, the mbtowc
() function inspects at most n
bytes of the multibyte string starting at s, extracts the next
complete multibyte character, converts it to a wide character and
stores it at *pwc. It updates an internal shift state known only
to the mbtowc
() function. If s does not point to a null byte
('\0'), it returns the number of bytes that were consumed from s,
otherwise it returns 0.
If the n bytes starting at s do not contain a complete multibyte
character, or if they contain an invalid multibyte sequence,
mbtowc
() returns -1. This can happen even if n >= MB_CUR_MAX, if
the multibyte string contains redundant shift sequences.
A different case is when s is not NULL but pwc is NULL. In this
case, the mbtowc
() function behaves as above, except that it does
not store the converted wide character in memory.
A third case is when s is NULL. In this case, pwc and n are
ignored. The mbtowc
() function resets the shift state, only
known to this function, to the initial state, and returns nonzero
if the encoding has nontrivial shift state, or zero if the
encoding is stateless.
Возвращаемое значение (Return value)
If s is not NULL, the mbtowc
() function returns the number of
consumed bytes starting at s, or 0 if s points to a null byte, or
-1 upon failure.
If s is NULL, the mbtowc
() function returns nonzero if the
encoding has nontrivial shift state, or zero if the encoding is
stateless.
Атрибуты (Attributes)
For an explanation of the terms used in this section, see
attributes(7).
┌───────────────────────────────┬───────────────┬────────────────┐
│Interface
│ Attribute
│ Value
│
├───────────────────────────────┼───────────────┼────────────────┤
│mbtowc
() │ Thread safety │ MT-Unsafe race │
└───────────────────────────────┴───────────────┴────────────────┘
Стандарты (Conforming to)
POSIX.1-2001, POSIX.1-2008, C99.
Примечание (Note)
The behavior of mbtowc
() depends on the LC_CTYPE
category of the
current locale.
This function is not multithread safe. The function mbrtowc(3)
provides a better interface to the same functionality.
Смотри также (See also)
MB_CUR_MAX(3), mblen(3), mbrtowc(3), mbstowcs(3), wcstombs(3),
wctomb(3)