Путеводитель по Руководству Linux

  User  |  Syst  |  Libr  |  Device  |  Files  |  Other  |  Admin  |  Head  |



   mbtowc    ( 3 )

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)