WCTOMB(3) Linux Programmer's Manual WCTOMB(3)
wctomb - convert a wide character to a multibyte sequence
int wctomb(char *s, wchar_t wc);
If s is not NULL, the wctomb function converts the wide character wc to
its multibyte representation and stores it at the beginning of the
character array pointed to by s. It updates the shift state, which is
stored in a static anonymous variable only known to the wctomb func-
tion, and returns the length of said multibyte representation, i.e. the
number of bytes written at s.
The programmer must ensure that there is room for at least MB_CUR_MAX
bytes at s.
If s is NULL, the wctomb function resets the shift state, only known to
this function, to the initial state, and returns non-zero if the encod-
ing has non-trivial shift state, or zero if the encoding is stateless.
If s is not NULL, the wctomb function returns the number of bytes that
have been written to the byte array at s. If wc can not be represented
as a multibyte sequence (according to the current locale), -1 is
If s is NULL, the wctomb function returns non-zero if the encoding has
non-trivial shift state, or zero if the encoding is stateless.
ISO/ANSI C, UNIX98
wcrtomb(3), wcstombs(3), MB_CUR_MAX(3)
The behaviour of wctomb depends on the LC_CTYPE category of the current
This function is not multi-thread safe. The function wcrtomb provides a
better interface to the same functionality.
GNU 1999-07-25 WCTOMB(3)