What Unicode encoding does the Linux kernel use?

http://www.xsquawkbox.net/xpsdk/mediawiki/Unicode says

Linux

On Linux, UTF8 is the native encoding for all strings, and is the format adopted by system routines such as fopen()

.

so Linux is similar to Plan 9 in this respect and boost :: filesystem and Unicode under Linux and Windows notes

It seems to me that boost::filesystem

under Linux does not provide a wide character string in path::native()

spite of boost::filesystem::path

being initialized with a wide string.

which excludes UTF-16 and UTF-32 as all variants require broad character support - NUL bytes are allowed inside strings.