fun io_write(buf: CString, from, len: Int): Int `{
size_t res = fwrite(buf+from, 1, len, self);
#ifdef _WIN32
// Force flushing buffer because end of line does not trigger a flush
fflush(self);
#endif
return (long)res;
`}
lib/core/file.nit:1520,2--1527,3