mbtowc()

Преобразовать многобайтовый символ в широкий символ

Прототип:

#include <stdlib.h>
                                       
int mbtowc( wchar_t *pwc,
            const char *s,
            size_t n );

Аргументы:

pwc

A pointer to a wchar_t object where the function can store the wide character.

s

NULL, or a pointer to the multibyte character that you want to convert.

n

The maximum number of bytes in the multibyte character to convert.

Библиотека:

libc

Описание:

The mbtowc() function converts a single multibyte character pointed to by s into a wide-character code pointed to by pwc, to a maximum of n bytes. The function stops early if it encounters the NULL character.

This function is affected by LC_TYPE.

The mbrtowc() function is a restartable version of mbtowc().

Возвращаемое значение:

• If s is NULL:

  0

  The mbtowc() function uses UTF-8 multibyte character encoding that's not state-dependent.

  ≠0

  Everything else.

• If s isn't NULL:

  0

  The s argument points to the NUL character.

  >0

  The number of bytes that comprise the multibyte character, to a maximum of MB_CUR_MAX (if the next n or fewer bytes form a valid multibyte character).

  -1

  The next n bytes don't form a valid multibyte character; errno is set.

Коды ошибок:

EILSEQ

Invalid character sequence.

Примеры:

#include <stdio.h>
#include <stdlib.h>
                                       
int main( void )
{
    char    *wc = "string";
    wchar_t wbuffer[10];
    int     i, len;
                                       
    printf( "State-dependent encoding? " );
    if ( mbtowc( wbuffer, NULL, 0 ) )
    {
        printf( "Yes\n" );
    } else {
        printf( "No\n" );
    }
                                       
    len = mbtowc( wbuffer, wc, 2 );
    wbuffer[len] = '\0';
    printf( "%s(%d)\n", wc, len );
                                       
    for ( i = 0; i < len; i++ )
    {
        printf( "/%4.4x", wbuffer[i] );
    }
                                       
    printf( "\n" );
        
    return (EXIT_SUCCESS);
}

Код генерирует следующий вывод:

$ ./a.out State-dependent encoding? No string(1) /0073

Классификация:

ANSI, POSIX 1003.1

Точка остановки потока

Нет

Обработчик прерываний

Нет

Обработчик сигналов

Да

В потоке

Да

Тематические ссылки:

btowc(), errno, mblen(), mbrlen(), mbrtowc(), mbsinit(), mbsrtowcs(), mbstowcs()

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