MBRTOWC(3)

NAME
mbrtowc - convert a character to a wide-character code (restartable)

LIBRARY
libc

SYNOPSIS
#include <wchar.h>
size_t
mbrtowc(wchar_t * restrict pwc, const char * restrict s, size_t n, mbstate_t * restrict ps);

DESCRIPTION
The mbrtowc() function inspects at most n bytes pointed to by s to determine the number of bytes needed to complete the next multibyte character. If a character can be completed, and pwc is not NULL, the wide character which is represented by s is stored in the wchar_t it points to.

If s is NULL, mbrtowc() behaves as if pwc was NULL, s was an empty string ("") and n was 1.

The mbstate_t argument, ps, is used to keep track of the shift state. If it is NULL, mbrtowc() uses an internal, static mbstate_t object, which is initialized to the initial conversion state at program startup.

RETURN VALUES
The mbrtowc() functions returns:

0   The next n or fewer bytes represent the null wide character (L'\0').

>0  The next n or fewer bytes represent a valid character, mbrtowc() returns the number of bytes used to complete the multibyte character.

(size_t)-2
    The next n contribute to, but do not complete, a valid multibyte character sequence, and all n bytes have been processed.

(size_t)-1
    An encoding error has occurred. The next fn or fewer bytes do not contribute to a valid multibyte character.

ERRORS
The mbrtowc() function will fail if:

[EILSEQ]
    An invalid multibyte sequence was detected.

[EINVAL]
    The conversion state is invalid.

SEE ALSO
mbtowc(3), multibyte(3), setlocale(3), wcrtomb(3)

STANDARDS
The mbrtowc() function conforms to isoC-99.