The fputwc function is the wide-character equivalent of the fputc function. It writes the wide character wc to stream. If ferror(stream) becomes true, it returns WEOF. If a wide character conversion error occurs, it sets errno to EILSEQ and returns WEOF. Otherwise it returns wc.
The putwc function or macro functions identically to fputwc. It may be implemented as a macro, and may evaluate its argument more than once. There is no reason ever to use it.
For non-locking counterparts, see unlocked_stdio(3).
The fputwc function returns wc if no error occurred, or WEOF to indicate an error.
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