printf

static VALUE
rb_f_printf(int argc, VALUE *argv)
{
    VALUE out;

    if (argc == 0) return Qnil;
    if (TYPE(argv[0]) == T_STRING) {
        out = rb_stdout;
    }
    else {
        out = argv[0];
        argv++;
        argc--;
    }
    rb_io_write(out, rb_f_sprintf(argc, argv));

    return Qnil;
}