MBTOWC(3) Library Functions Manual MBTOWC(3)

mbtowc, mbtowc_lconvert a character to a wide-character code

Standard C Library (libc, -lc)

#include <stdlib.h>

int
mbtowc(wchar_t *restrict pwc, const char *restrict s, size_t n);

#include <stdlib.h>
#include <xlocale.h>

int
mbtowc_l(wchar_t *restrict pwc, const char *restrict s, size_t n, locale_t loc);

The () function converts a multibyte character s into a wide character, according to the current conversion state, and stores the result in the object pointed to by pwc. Up to n bytes are examined.

A call with a null s pointer returns nonzero if the current encoding requires shift states, zero otherwise; if shift states are required, the shift state is reset to the initial state.

While the () function uses the current locale, the () function may be passed a locale directly. See xlocale(3) for more information.

If s is NULL, the mbtowc() function returns nonzero if shift states are supported, zero otherwise.

Otherwise, if s is not a null pointer, mbtowc() either returns 0 if s represents the null wide character, or returns the number of bytes processed in s, or returns -1 if no multibyte character could be recognized or converted. In this case, mbtowc()'s internal conversion state is undefined.

The mbtowc() function will fail if:

[]
An invalid multibyte sequence was detected.
[]
The internal conversion state is invalid.

btowc(3), mblen(3), mbrtowc(3), mbstowcs(3), multibyte(3), wctomb(3), xlocale(3)

The mbtowc() function conforms to ISO/IEC 9899:1999 (“ISO C99”).

April 11, 2004 macOS 15.2