вывод символов (character output)
Смотри также (See also)
Section 2.5, Standard I/O Streams, btowc(3p), fputwc(3p),
fwscanf(3p), mbrtowc(3p), setlocale(3p)
The Base Definitions volume of POSIX.1‐2017, Chapter 7, Locale,
inttypes.h(0p), stdio.h(0p), wchar.h(0p)
