WCRTOMB(3) Library Functions Manual WCRTOMB(3)
wcrtomb -- converts a wide character to a multibyte character
Standard C Library (libc, -lc)
wcrtomb(char * restrict s, wchar_t wc, mbstate_t * restrict ps);
wcrtomb() converts the wide character given by wc to the corresponding
multibyte character, and stores it in the array pointed to by s unless s
is a null pointer. This function will modify the first at most
MB_CUR_MAX bytes of the array pointed to by s.
The behaviour of wcrtomb() is affected by the LC_CTYPE category of the
These are the special cases:
wc == 0 For state-dependent encodings, wcrtomb() stores a nul byte
preceded by special byte sequence (if any) to return to an
initial state in the array pointed to by s, and the state
object pointed to by ps also returns to an initial state.
s == NULL wcrtomb() just places ps into an initial state. It is
equivalent to the following call:
wcrtomb(buf, L'\0', ps);
Here, buf is a dummy buffer. In this case, wc is ignored.
ps == NULL mbrtowc() uses its own internal state object to keep the
conversion state, instead of ps mentioned in this manual
Calling any other functions in Standard C Library (libc,
-lc) never changes the internal state of mbrtowc(), which
is initialized at startup time of the program.
positive The number of bytes (including any shift sequences) which
are stored in the array.
(size_t)-1 wc is not a valid wide character. In this case, wcrtomb()
also sets errno to indicate the error.
wcrtomb() may cause an error in the following case:
[EILSEQ] wc is not a valid wide character.
[EINVAL] ps points to an invalid or uninitialized mbstate_t
The wcrtomb() function conforms to ISO/IEC 9899/AMD1:1995 (``ISO C90,
Amendment 1''). The restrict qualifier is added at ISO/IEC 9899:1999
NetBSD 6.1.5 February 4, 2002 NetBSD 6.1.5