Availability:C-language interface function
int Ssnprintf(char
*buf, size_t size, const char *fm, ...)Print to a C string, emitting a maximum of size bytes while
ensuring buf is 0-terminated. The buf is written
using UTF-8 encoding. Unlike snprintf(), the return value is the
number of logical code points written rather than the number of bytes
and if the buffer is too small, -1 is returned rather than
the number of bytes that would be written. Future versions may improve
compatibility with the POSIX functions.