dyad_writef is certainly not 'async' when using the 'r' input specifier (which seems to redirect input from a FILE* to the output stream). And the way dyad_writ

dyad_writef is certainly not 'async' when using the 'r' input specifier (which seems to redirect input from a FILE* to the output stream). And the way dyad_writef achieves 'async' is to buffer the entire contents of the output in RAM. So for 'r', why bother using the FILE* formatted IO if all you're going to do is pull single characters at a time? You can just use file descriptors.