The putwchar function is the wide-character equivalent of the
putchar function. It writes the wide character wc to
stdout. If ferror(stdout) becomes true, it returns WEOF. If a
wide character conversion error occurs, it sets errno to EILSEQ
and returns WEOF. Otherwise it returns wc.
For a non-locking counterpart, see unlocked_stdio(3).
The behaviour of putwchar depends on the LC_CTYPE category of the current
It is reasonable to expect that putwchar will actually write the
multibyte sequence corresponding to the wide character wc.